General

adamantine
Having a luster like that of a diamond

aigrette
A piece of jewellery shaped like a feather that is usually worn on the hair or on a hat

art deco
A style of jewellery that originated in Paris and was popular from the mid 1920s to the 1930s. Art Deco jewellery is characterised by hard lines and angles rather than curves

art nouveau
A style of jewellery popluar from the late nineteenth century until about 1918. Art nouveau jewellery is characterised by gentle curves and organic designs

assay
A test of the purity or fineness of an alloy, carried out by an official organization.

assay mark
The official mark or series of marks on a piece of jewellery that identifies the purity or fineness of the alloy used in it as well as its maker or designer. Also known as a hallmark

asterism
The luminous property that some gemstones like Star Sapphires have, whereby their inclusions are aligned in such a way that they reflect light in the pattern of a 4, 6 or 12 rayed star

bail
The finding on top of a pendant that allows it to be attached to a necklace

band
A ring of uniform width, which may or may not be set with gemstones

bandeau
A piece of jewellery in the form of a narrow band that is usually worn on the forehead

bangle
A rigid bracelet, which can either be work by opening with a clasp and hinge, or by slipping directly over the hand

barette
A piece of jewellery that is usually worn on the hair

belle epoque
French for 'beautiful period'. A style of jewellery popular during the Edwardian period, or the reign in England of Edward VII during the first decade of the twentieth century. Belle Epoque jewellery is characterised by its delicacy and elegance, use of filagree work, bow motifs and pearls and diamonds

bib
A short necklace, usually with pendants or other ornaments hanging from the front . Also known as a collarette

bodkin
A heavily jeweled ornament for the hair, popular during the Renaissance period

bracelet
A piece of jewellery worn around the wrist. Various types of bracelets include bangles, cuffs, expansion bracelets, spiral bracelets and link bracelets

butterfly
The finding at the back of a earring that is screwed or slid onto the earring to attach it securely to the ear. Also known as a scroll

cabochon
A stone that has a smooth, rounded or dome-like surface that has been cut and polished but does not have facets

cameo
A miniature relief carving on a stone, almost always a portrait of a woman in side-profile. Two colour cameos are achieved by layering a different coloured substrate under the stone that will be carved

carat
The standard measure of weight used for gemstones, introduced in 1907. One carat (ct.) is equivalent to 0.2 grams. A carat is divided into 100 points

carbuncle
A cabochon garnet

champlevé
French for 'raised field'. A technique in which enamel is filled in recesses that have been carved or stamped into a metal substrate

chatelaine
A belt or girdle that is used to suspend various implements including an etui

chaton
A gemstone that has been set with a backing of reflective metal foil

chatoyance
The luminous property that some gemstones have, whereby their inclusions are aligned in such a way that they reflect light in thin bands that make the stone resemble a cat or tiger's eye. This effect is usually only seen in cabochon stones

clasp
A fastening mechanism that opens and closes to attach and detach the two ends of a piece of jewellery like a bracelet or necklace. The assay mark and maker's assay are usually inscribed on the clasp of a piece of jewellery. Some common types of clasps include the spring right, the barrel, the lobster claw and the hook and eye.

claw
A metal prong that securely holds a gemstone in its setting

cloud
A type of inclusion in gemstones that looks like a milky area or cloud. Clouds are usually clusters of smaller inclusions

cocktail ring
A large or oversized ring set with precious or semiprecious stones

collarette
See bib

collier
A wide necklace that encircles the neck from the collar bone to the chin

colour change
See dichroism

composite suite
A piece of jewellery that is composed of more than one part, where each part may be worn separately or together as a single piece

cuff
A rigid and relatively wide bracelet, resembling the cuff of the shirt

demilune
A gemstone that is shaped like a half moon

demi-parure
A small matching set or suite of jewellery, usually comprising a necklace and a bracelet, or a pair of earrings and a brooch

diadem
A semi-circular or circular piece of jewellery worn on the head. Also known as a tiara

dichroism
The luminous property that some minerals and gemostones have, whereby they appear to have more than one colour particularly when viewed from different angles. Also known as colour change

enamel
A substance made of powdered glass and colouring agents can be fused onto various metals and is used to decorate pieces of jewellery.

enhanced
A gemstone that has been treated to improve one or more of its characteristics including colour, clarity and strength. Some common enhancements are heating, oiling or coating the surface, irradiation, filling cracks and dyeing

eternity ring
A narrow ring with diamonds or gemstones set all around it

etui
A small ornamental case, often shaped like a cylinder, meant to carry small items like spectacles. Also known as a necessaire

feather
A type of inclusion in gemstones that starts at its surface and extends to its interiors, also known as a fracture

ferroniere
A piece of jewellery in the form of a narrow band with a single central gemstone that is usually worn on the forehead

finding
A functional component of a piece of jewellery, including settings, joints, clasps, hooks and backs

fineness
The proportion of silver or gold in their alloys, usually experessed in parts per thousand

fine gold
Pure gold, rather than an alloy with only a certain percentage of gold

fine silver
Pure silver, rather than an alloy with only a certain percentage of silver

fire
The luminous property that some gemstones like opals have, whereby they appear to have several vivd colours within them

flaw
An imperfection in a gemstone, including fissures, cracks, inclusions of other minerals and air or liquid filled cavities. Flaws usually reduce the value of a gemstone, except in some rare cases

floater
A necklace where gemstones or pearls are strung on almost invisible string, so that they appear to float on the neck

flourescence
The luminous property that some gemstones like diamonds have, whereby they emit light or radiation when exposed to ultraviolet light

foilback
A gemstone that has a thin metallic foil backing it to make it more reflective and enhance its sparkle

fracture
See feather

gerlot
A relatively small, but long gemstone or pearl pendant

gimmel ring
A ring made up of two or more linked hoops that fit together and appear as a single ring

girandole
A piece of jewellery in which three pear shaped gemstones or pearls hang from a larger one or a decorative motif like a bow, most commonly seen in earrings and brooches

graduated
A series of pearls or gemstones, most commonly in the form of a necklace, arranged by size from smallest at either end, to largest in the center

hallmark
See assay mark

hardness
The measure of how resistant a gemstone is to being scratched. The Mohs Scale of hardness ranges from 1 to 10, with 10 being the hardest. Diamonds are rated 10 on the Mohs Scale

heat treatment
A method of enhancing the colour of gemstones by heating them to a very high temperature

inclusion
A small particle of another mineral, liquid, gas or some foreign matter that is contained within a gemstone

inlay
The decorative practice of embedding a material such as polished stone or glass in another material like metal, where the surface of both is perfectly level

iridescence
The luminous property that some gemstones like opal and moonstone have, whereby they appear to contain many different and changing colours

jabot
A jewelled tie pin, popular during the Art Deco period

karat
The unit of measure for the fineness of gold. Fine gold is 24 karat (Kt). Other common standards are 18Kt (750 fineness), 14Kt (583 fineness), and 10Kt gold (417 fineness)

knot
A type of inclusion at the surface of polished gemstones that appears as a minute bump

lapidary
A person who cuts and polishes gemstones

lavalier
A long pendant with a dangling stone meant to hang from a necklace

ligne
A unit of measure used to determine the width of a bracelet. 40 lignes are equal to 1 inch

loupe
A device used by jewellers and lapidaries to magnify and inspect gemstones, ususally to the power of 10

luster
The sheen of a gemstone or pearl, or the nature and intensity of the light it reflects

mandrel
A graduated, marked cone that is used to measure the size of rings. A ring is placed on the cone and its size is taken as the level on the cone where is fits snugly. The measure of ring size varies in different countries

Minaudière
A small, hard vanity case made of metal or wood that is carried in the hand and may be set with gemstones

mixed cut
A gemstone in which the cut or style of faceting above and below the girdle differ from each other

Mohs Scale
See hardness

necessaire
See etui

necklace
A piece of jewellery that is worn around the neck. Various types of necklaces, based on their length, include choker, princess, matinee, opera and rope

negligee
A long necklace that terminates in tassles or drops of irregular length

oiling
A method of enhancing the colour of gemstones and masking their inclusions by applying mineral oil on it

pampilles
A cascade of drop shaped gemstone or pearl pendants, intended to resemble raindrops

parure
French for 'personal ornamentation'. A matching set or suite of jewellery, usually comprising four or more pieces including a necklace, a pair of earrings, a brooch and one or two bracelets

passamenterie
Pieces of jewellery whose design is inspired by the trimmings on antique furniture like cords

pendaloque
A brilliant cut gemstone that is shaped like a pear or tear drop, and usually suspended from a smaller stone separated from it by a motif like a bow

pleochroic
The luminous property that some minerals and gemostones have, whereby they appear to have more than two colours particularly when viewed from different angles

pomander
A small, ornamental bottle containing perfume or other aromatics that is usually worn as a pendant

ring
A piece of jewellery that is work around the finger.

rivière
A choker length necklace that is usually made up of a continuous line of graduated or equal sized gemstones

sautoir
A necklace longer than thirty inches that usually has a pendant or other ornament at its end, and was popular during the Belle Epoque period

scatter pin
A group of small pins or brooches that are usually worn together

scroll
See butterfly

setting
The method of securing a gemstone to a piece of jewellery, usually metallic. There are nummerous kinds of settings, inlcuding arcade, bezel, channel, coronet, collet, chaton, and pave

sévigné
A piece of jewellery usually in the shape of a bow, worn as a bodice ornament

solitaire
A simple piece of jewellery, usually a ring, set with a single gemstone, most often a diamond

stomacher
A large, triangualr piece of jewellery, usually extending from the neck to the waist and worn as a bodice ornament

tiara
See diadem

tie bar
A piece of men's jewellery used to clasp the two parts of a necktie together

torsade
See bayadère

trapichism
The property that some gemstones have, whereby they appear to have star shaped rays emanating from their center due to the presence of black carbon impurities within them

trembler
A piece of jewellery that has some of its parts set on stiff wires or springs so that they move when they are worn

troy weight
A system of measure for the weight of precious metals. 1 troy pound is equal to 12 troy ounces or 240 pennyweights (Dwt) or 576 grains

vermeil
Gold plated or gilded silver

vinaigrette
A small ornamental bottle, meant to carry smelling salts or other aromatics

Indian

adosa
A historical term for flawless diamonds

almas
See heera

amrapali
A style of handcrafted silver and gold jewellery. Amrapali was the name of a royal courtesan of the Vaishali Republic in India (around 500 BC) who was considered the most beautiful and cultured lady of her time

anguthi
A ring, or piece of jewellery worn around the finger. Also known as angushtari

angushtari
A earring, or piece of jewellery worn on the ears

antiyan
See bali

anwat
A toe ring, specifically for the big toe

anwat paon
A toe ring, or piece of jewellery worn around the toes. Also known as bichhua

baglus
See baksua

bali
A earring, usually in the shape of a circle

balu
A nose ornament, or piece of jewellery worn on the nose. Also known as besar, nath and nathni

baksua
A piece of jewellery worn at the waist as a buckle. Also known as baglus

bazuband
An armlet or arm band, or piece of jewellery worn around the upper arm. Also known as bhujband, dand and joshan

besar
See balu

bhujband
See bazuband

bichhua
See anwat paon

bindu
See moti

bulak
A nose ornament, usually suspended from the septum

bulla
A pendant. Also known as dhuk-dhuki and padak

carapuch
Spinel

chakriyan
A pair of earrings, usually in the form of studs

challa
A ring, usually in the form of a broad and heavy band set with gemstones or pearls

champakali
A type of necklace that is designed to appear like buds of the champa or frangipani flower that have been strung together

chandbala
Also known as pankhiyan

chau
A historical Indian unit of measurement used for pearls. Also known as chov

chintak
A necklace, usually of choker length and designed to hug the neck

chov
See chau

chowkaray
A style of setting gemstones or pearls in a cluster of four

chudamani
A piece of jewellery worn on top of the head. Also known as chudaratna

chudaratna
See chudamani

chudo
A bangle, or rigid piece of jewellery worn around the wrist. Also known as kangan, kangni, kada, karay and patri

chur
A bracelet, or piece of jewellery worn around the wrist. Also known as dasti and dastband

dand
See bazuband

dastband
See chur

dasti
See chur

dhuk-dhuki
See bulla

gajrah
A bracelet traditionally made of gold and pearls

ghariyal
Watch

goshwara
Gemstones or pearls suspended as drops in a piece of jewellery

gundiyan
Buttons

har
A necklace, or piece of jewellery worn around the neck

heera
Diamond. Also known as ilmas or almas

ilmas
See heera

indranila
See nilam

jadau
See kundan

jadtar
See kundan

jhumke
karanphool

jhumar
A piece of bridal jewellery worn on the head

jigha
See sarpech

joshan
See bazuband

kalghi
A piece of jewellery, usually in the shape of a single plume, worn as a turban ornament

kangan
See chudo

kangni
See chudo

kada
See chudo

karay
See chudo

koftgari
A style of jewellery created by engraving a pattern on a metal surface and then laying fine gold or silver wire in the grooves. Also known as false damascening

kundan
Kundan refers to fine or highly refined gold foils, and and is sometimes used to describe the champleve style of setting gemstones with such foils rather than claws or rims in recesses that have been hollowed out in gold and surfaced with coloured minerals. This setting technique or style is also known as jadau or jadtar

laldi
See larli

larli
Spinel; sometimes used for ruby. Also known as laldi

lu lu
A pair of earrings, usually in the form of drops or hanging pendants

maangtika
See tika

manikya
Ruby. Also known as yakhoot

marakat
See panna

marvareed
See moti

meena
Enamel

meenakaari
The art of decorating or embellishing metal with different coloured enamel, often used to ornament traditional Indian jewellery

moti
Pearl. Also known as bindu and marvareed

nagi
See ratna

nath
See balu

nathni
See balu. Nathnis are usually smaller varieties of nose ornaments

navratan
Literally 'nine stones'. A style of jewellery in which nine types of precious and semiprecious gemstones are used, corresponding to the nine planets of Vedic astrology. The gemstones are ruby, pearl, red coral, emerald, yellow sapphire, diamond, blue sapphire, hessonite and cat's eye

nilam
Blue sapphire. Also known as indranila

nug
See ratna

pachchikam
A style of jewellery in which polki or uncut diamonds are foil backed and set in silver

padak
See bulla

paizeb
See payal

pankhiyan
See chandbala

panna
Emerald. Also known as marakat and zamarrud

parab
A flat, table cut diamond

patri
See chudo

payal
An anklet, or piece of jewellery usually worn around the ankle. Also known as paizeb and tora paon

polki
A diamond that has few facets and appears to have little fire or brilliance. Sometimes used to refer to unpolished or rough diamonds. Polkis are frequently used in kundan and jadau jewellery

poonak
See rati

pukhraj
Yellow sapphire

rati
A unit of weight used to measure gemstones and pearls in India. One rati is equivalent to 0.91 carats, but is known to vary slightly across different regions. Also known as poonak

ratna
Gemstone. Also known as nagi and nug

rawakam
A style of jewellery that uses solid granules of precious metals like gold or silver as decorative elements

sankh
Conch shell

sarpatti
A piece of jewellery, usually in the shape of a horizontal band, worn as a turban ornament

sarpech
A piece of jewellery, usually in the shape of a plume in the center of a horizontal band, worn as a turban ornament. Also known as jigha

tank
A unit of weight used to measure gemstones and pearls in India. One tank is equivalent to 24 ratis or 72 grains

taveez
Amulet

tikka
See teeka

teeka
A piece of bridal jewellery usually worn on the head, with a pendant hanging on the forehead. Also known as tikka or maangtika

thappa
A style of jewellery created by melting metal and then hammering it into the desired shape

thewa
A style of jewellery in which sheets of 24 karat gold foil are patterned by piercing and then applied to coloured glass that is foil backed and mounted in settings

tola
A unit of weight used to measure precious metals in India. One tola was traditionally the weight of 100 tola seeds; today, one tola is equivalent to 1.66 grams or 0.375 troy ounces

tora
Chain

tora paon
See payal

turra
A jewelled tassle with a stem, usually worn as a turban ornament

vanki
A rigid arm band, or piece of jewellery worn around the upper arm

vilandi
See polki

yakhoot
See manikya; sometimes used for spinel

zabarjad
Peridot

zamarrud
See panna

Diamonds

bort
A term for industrial grade diamonds, usually used in cutting applications

brilliance
The brightness that appears to emanate from within a diamond, due to the reflection of light that falls on the table back through the same facet

canary
A common descriptive term for deep yellow coloured diamonds

carat weight
The weight of a diamond measured in carats. One carat (ct.) is equivalent to 0.2 grams. A carat is divided into 100 points

carbonado
A rare, almost opaque black diamond of industrial grade, usually used in cutting and grinding applications. Most of the known carbonado diamonds have been found in Brazil

champagne
A common descriptive term for light brown or pinkish brown coloured diamonds

clarity
The clearness of a diamond, or the measure of the amount of flaws and inclusions of other minerals in a diamond. The clarity scale for diamonds ranges from F (internally and externally flawless) to I3 (having several inclusions that can be seen by the naked eye and detract from the beauty and durability of the stone). For the entire scale, click here. The clarity of diamonds is usually examined using a ten-power loupe, which magnifies the stone to ten times its size

coffee
A common descriptive term for deep brown coloured diamonds

colour
A measure of the saturation of a diamond. The diamond colour scale ia alphabetic, ranging from D (transparent or completely colourless) to Z (having a visible yellow tinge). Fancy, or deeply coloured diamonds are rated on a different scale, and are most commonly black, yellow, orange and brown. Other rarer colours include pink, purple, blue, red and green. For more information on diamond colour, click here

cognac
A common descriptive term for orangy brown coloured diamonds

crown
The part of a cut diamond that lies above the girdle

crown angle
The angle at which the main facets of a diamond's crown instersect with the plane of its girdle

culet
The small facet that forms the base of a brilliant cut diamond or gemstone and prevents it from being chipped

cut
The way in which a diamond has been faceted and proportioned, including but not limited to its shape. For more information on various diamond cuts and shapes, click here

depth
The height of a diamond, measured from the table to the culet, expressed in milimeters

depth percentage
The ratio of a diamond's depth to its width

diameter
The measure of a diamond's girdle, or its widest perimeter

diamond guage
An instrument used to measure a diamond's length, width and depth in milimeters

dispersion
The luminous property of a diamond, whereby it splits white light into its component wavelengths or colours. Also known as fire

exhausted mines
Mines that no longer produce diamonds, as their supply has been exhausted. Some important exhausted mines include Golconda in India, Kimberly in South Africa and Mirna in Russia

facet
One of the several smooth, flat faces on the surface of a cut diamond

fire
See dispersion

flouresecence
The luminous property that some diamonds have, whereby they emit light or radiation when exposed to ultraviolet light

girdle
The widest perimeter of a cut diamond, which may or may nor be polished or faceted and divides the crown from the pavilion

grain
A unit of weight used for diamonds and natural pearls. One grain is equal to 0.25 carats or 25 points

irradiated
A diamond that has been exposed to radiation in a cyclotron to change its colour to a pale green or aquamarine

mélée
A diamond that weighs less than 0.2 carats or 20 points

natural
A type of inclusion where tiny areas of unpolished surface of the original rough diamond remain on a polished diamond

pavilion
The part of a cut diamond that lies below the girdle

pavilion angle
The angle at which the main facets of a diamond's pavilion instersect with the plane of its girdle

point
One hundredth of a carat, or 0.002 grams

scintillation
The luminescence or flashes of light that are produced by a diamond when it is exposed to radiation of any kind

symmetry
The alignment of a diamond's facets, relative to its axes of symmetry, used as an indicator of the quality of a diamond's cut

table
The usually large, flat facet that forms the top of a cut diamond or gemstone

table percentage
The ratio of the diameter of a diamond's table to it's entire diameter

Pearls

abas
A unit of weight historically used to measure natural pearls in Persia. One abas is eqivalent to 0.91 carats

akoya
The Japanese term for natural or cultured pearls that come from the akoya-gai mollusk

akoya keshi pearl
A small pearl that is produced by the akoya-gai mollusk as a byproduct of cultured akoya pearl production

alabaster pearl
An imitation pearl made from an alabaster bead that has been coated with lusterous laquer

antilles pearl
An imitation pearl made from the spindle of a turbo shell

awabi
The Japanese term for pearls that come from abalone shells

baroque
Irregularly shaped pearls, which may be natural or cultured

basra pearl
A natural saltwater pearl sourced from the Persian Gulf and named after the town of Basra in Iraq. These pearls are not harvested any longer

bayadère
A pearl necklace composed of several strands that have are twisted or intertwined. Also known as torsade

biwa pearl
Freshwater pearls sourced from Lake Biwa in Japan. Biwa pearls are usually irregular in shape and more lustrous than other freshwater pearl varieties

black pearl
A pearl produced by a black-lipped oyster found in the tropical waters of the Indian and Pacific Oceans. The various colours of black pearls include grey, peacock green, purple and dark brown, and they can have additional overtones of blue, green, pink, gold or silver. The colour of black pearls depends on the combination of minerals in the oyster's environment, which it injests. Also known as Tahitian pearls

blister pearl
Blister pearls, also known as bouton or mabe pearls, are those pearls that remain attached to the mollusk's shell during their development. These pearls need to be physically cut from the shells, resulting in a hemispherical or dome shape

bodycolour
The primary colour of the surface of a natural or cultured pearl

bouton pearl
See blister pearls

circled pearl
A pearl with raised rings around its surface, caused by the pearl's rotation during its development in the mollusk

colour
The combination of bodycolour and overtone of a pearl. Colour is one of the factors considered when grading natural and cultured pearls

condari
A unit of weight historically used to measure natural pearls in China. Condari was based on the weight of a grain of rice

cultured pearl
A pearl produced by a mollusk as a result of a foreign object, usually a minute piece of mother of pearl, that has been artificaially introduced or nucleated into its shell

dust pearl
The historical term used for seed pearls

freshwater pearl
Those pearls that are harvested from mollusks living in freshwater, usually irregular in shape

grain
A unit of weight used for diamonds and natural pearls. One grain is equal to 0.25 carats or 25 points

hammer pearl
A natural dark brown or black pearl produced in the hammer-shell mollusk

hinge pearl
A natural pearl found near the hinge of a mollusk, usually irregular and elongated in shape

imitation pearl
A material that simulates the appearance of a natural or cultured pearl, but does not possess its physical properties

irridescence
The luminous property of pearls, whereby their layers of nacre splits white light into its component colours giving their surface a shimmering or irridescent appearance

luster
The sheen or surface brilliance of a pearl, or the quantity and quality of light it reflects. The luster of a pearl depends on the thickness of its nacre. Luster is one of the factors considered when grading natural and cultured pearls

mabe pearl
A cultured hemispherical bouton or blister pearl

mississippi river pearl
Freshwater pearls sourced from the Mississippi River in the United States. Mississippi River pearls are usually irregular and elongated in shape

momme
A unit of weight used to measure cultured pearls in Japan. One momme is equivalent to 3.75 grams

nacre
The crystalline substance made of aragonite and calcite crystals bound together by conchiolin, which mollusks like oysters secrete around foreign objects within their shells, layers of which eventually form a pearl

natural pearl
A pearl produced by a mollusk as a result of a foreign object that has naturally entered its shell

non-nacreous pearl
A natural pearl that does not have a nacreous surface layer, like pearls produced by clams, conches and scallops

orient
A characteristic of the irridescence or luster of natural and cultured pearls

overtone
The secondary colour of the surface of a natural or cultured pearl, created when the layers of nacre split white light into its component colours

peacock
A rare variety of black or Tahitian pearls that have a dark green colour and overtones ranging from pink to purple

rice pearl
A small, irregular freshwater pearl that resembles a grain of rice, usually having a textured surface rather than a smooth one

rope
A string of pearls that is more than forty inches long, usually doubled or tripled and worn as a necklace

saltwater pearl
Those pearls that are harvested from mollusks living in saltwater

seed pearl
A natural, round pearl that weighs less than 0.25 grains, and measures less than 2mm in diameter

shape
The overall shape of a pearl ranging from perfect round to baroque. Cultured pearls are also available in fancy shapes like hearts, dragons, flowers and crosses based on the shape of the nucleus that is implanted in them. Shape is one of the factors considered when grading natural and cultured pearls

size
The measure of a pearl's diameter, expressed in milimeters. Size is one of the factors considered when grading natural and cultured pearls

south sea pearl
A natural or cultured pearl produced by the mollusk Pinctada maxima, usually having a yellow or gold bodycolour

surface
The smoothness of a pearl, which may be interrupted by blemishes or flaws. The number of blemishes, along with their size and location affect the value of a pearl. Surface is one of the factors considered when grading natural and cultured pearls

tahitian pearl
See black pearls

wax pearl
A hollow glass bead that has been filled with wax to resemble a pearl

Stones

agate
A semiprecious gemstone that is a variety of microcrystalline quartz, and is found in a wide range of colours ranging from black and red to greeen and blue and white. Various colours of agate may appear in the same stone as flecks or bands. Agate has a hardness of 6.5-7 on the Mohs Scale

alexandrite
A semiprecious gemstone that is from the beryl family and appears to have different colours depending on the light it is viewed in, ranging from red to blue and green. Alexandrite has a hardness of 8.5 on the Mohs Scale

amber
The translucent, fossilized sap or resin of conifer trees that ranges in colour from white and pale yellow to deep red, black and blue. Amber is used in jewellery and has a hardness of 2.5 on the Mohs Scale

amethyst
A semiprecious gemstone that is a variety of crystalline quartz and ranges in colour from green to pale purple to deep violet. Amethysts may be opaque or tanslucent

aquamarine
A transparent semiprecious stone from the beryl family that is light green or blue and may be faceted or cut as a cabochon. Aquamarine has a hardness of 7.5-8 on the Mohs Scale

beryl
A mineral that comes in several colours including green, blue and red. Emerald, aquamarine and morganite are all forms of beryl. Beryl has a hardness ranging from 7 to 8 on the Mohs Scale

citrine
French for 'lemon'. A semiprecious type of quartz that ranges in colour from pale yellow to deep gold. Citrines have a hardness of 7 on the Mohs Scale

coral
The hard calcium carbonate structure secreted by marine animals, also called coral, that can be cut, polished and used to make jewellery. Coral can come in several colours including pink, orange, red, white and black. Coral has a hardness of 3.5 on the Mohs Scale

corundum
A mineral that comes in several colours including ruby and sapphire, depending on the metallic oxides that it contains. Corundum that does not contain any oxides is colourless and known as pure corundum or white sapphire. Rubies contain chromic oxide, blue sapphires contain oxides of titanium and yellow sapphires contain ferric oxide. Corundum has a hardness of 9 on the Mohs Scale

emerald
A hard, green compound of beryl that is coloured by chromium and vanadium impurities. Emeralds are commonly included or flawed, and therefore frequently oiled, irradiated or dyed to enhance their colour. Emeralds may also be synthetically created in a laboratory. Emeralds have a hardness of about 7.5 on the Mohs Scale

garnet
A group of semiprecious stones that range in colour from red to green and yellow. Garnets have a hardness of 6-8 on the Mohs Scale

jade
A semiprecious gemstone of either jadeite or nephrite that can be either translucent or opaque, and ranges in colour from green, white and lilac to brown and black. Nephrie can be carved into several different shapes and is often used in applications other than jewellery. Jadeite, used for jewellery, is classified into types from A to C, based on its colour and enhancements

moonstone
A translucent gemstone ranging in colour from whitish-blue to orange. Moonstones are almost always cut as cabochons and were popular in Art Nouveau jewellery. They have a hardness of 6.5-7 on the Mohs Scale

mother of pearl
The irridescent coating found on the inside of abalone or oyster shells that is used in jewellery as well as other applications

obsidian
A lustrous compund of silica found in volcanic lava flows that is usually black, but can be found in grey, red, brown and green varieties. Obsidian has a hardness of 5 on the Mohs Scale

onyx
A semiprecious stone that is a form of agate, usually with parallel bands of black and white

opal
An irridescent semiprecious stone with inclusions of many colours that give it fire, and a high water content. Opals have a hardness of 5.5-6.5 on the Mohs Scale

peridot
A yellowish-green semiprecious stone, usually from the volcanic island of St. John in the Red Sea. Peridots have also been discovered in meteorites. Peridots have a hardness of 6.5 on the Mohs Scale

ruby
A precious gemstone from the corundum family that range in colour from light pink to deep red. Rubies have a hardness of 9 on the Mohs Scale

rock crystal
A transparent or translucent semiprecious gemstone. Rock crystal is the purest form of the crystalline mineral, quartz.

sapphire
A precious gemstone from the corundum family that is available in several colours including blue, green, yellow, pink, purple and white, depending on the metallic oxides it contains. Sapphires have a hardness of 9 on the Mohs Scale

spinel
A hard, semiprecious gemstone that ranges in colour from red to black, often resembling a ruby. Spinels can also be blue, green and yellow, depending on the concentration of iron compounds within them. Spinels have a hardness of 8 on the Mohs Scale

topaz
A semiprecious gemstone that can be found in the colours blue, brown, yellow and pink. Other colours of topaz can be created through enhancements like heat treatment. Topaz has a hardness of 8 on the Mohs Scales

tourmaline
A semiprecious gemstone that is available in a wide range of colours, and that can appear to have more than one colour in itself. Tourmaline has a hardness of 7-7.5 on the Mohs Scale

turquoise
A semiprecious gemstone of bluish-green colour that is made of a copper and aluminium compound with a high water content. Turquoise is named after Turkey, where it was thought to have been discovered. Turquoise has a hardness of 6 on the Mohs Scale

zircon
A semiprecious gemstone that ranges in colour from brown and violet to blue, red and colourless. Zircon has a hardness of 7.5 on the Mohs Scale

Watches

aperture
The space on the face of a watch in which the date is displayed

analog
A watch that uses hands to show the time rather than an LCD display

atmosphere
The unit of pressure used to describe the water resistance of a watch

atomic time standard
A watch that sets its time automatically by receiving radio signals from an extremely accurate atomic clock

automatic
A watch that uses the movements of the wearers hand to move an oscillating weight within it, keeping the mainspring wound, eliminating the need to manually wind it. Also known as kinetic

balance wheel
The regulating organ of a watch, which vibrates on a spiral hairspring whose lengthening or shortening causes the balance wheel to move faster or slower, advancing or retarding the watch

bezel
The ring that surrounds the face of the watch and holds its protective crystal in place. Bezels may rotate around the face of the watch, to calculate elapsed time amongst other applications

caliber
A descriptive term for the size and configuration of the movement of a watch, its shape and its origin

case
The chasis or body of a watch, which houses its mechanism and to which its strap or band is fixed

case back
The cover on the back of a watch, which protects its mechanism. The case back is usually inscribed with the watch maker's mark and other information regarding the watch

chronograph
The stopwatch or timer mechanism of a watch that can be started, paused, stopped and reset independently from the watch. Also refers to multifunction watches built for sporting applications that have two or three dials on their face to measure seconds, minutes and hours

chronometer
A watch that is certified to satisfy official standards of precision by having been set under various position and temperature conditions

complication
A watch function other than basic time keeping. Some popular complications include chronographs, minute repeaters, tourbillions and perpetual calendars

corrector
The system in which the crown of a watch is used to set its time

crown
The knob or button that extends from the case of a watch and is used to set its time and date

crystal
The transparent, protective cover over the face of a watch. Crystals may be made out of acrylic, a hard composite of minerals, or sapphire. Also known as glass

deployment buckle
A clasp with three parts that folds in the shape of the letter Z. When it is flat or open, the watch strap is wide enough to slip over the hand, and when it is folded or closed, the watch fits snugly around the wrist. Also known as a fold over buckle

dial
The visible surface of a watch that lies below its crystal and on top of its mechanism, usually inscribed with markings used to tell the time. Also known as face

digital
A watch that uses an LCD display to show the time rather than hands

dual timer
A watch that measures the time of at least one other location in addition to the current local time

eco drive
A watch that is powered by natural or artificial light rather than a battery, and recharges consantly to run eternally

face
See dial

flyback
An additional hand on chronograph watches that can be independently stopped to record the fist finsih time or a lap time. When restarted, the flyback catches up with the second hand that continued to move when it was stopped

fold over buckle
See deployment buckle

glass
See crystal

hands
The pointing devices of an analog watch that circle around its dial indicating the time and any other speacial feature the watch may have. The various styles of hands include alpha, baton, dauphine, luminous and skeleton, amongst others

horology
The science of measuring time, including the design and construction of timepieces

jewel
A synthetic sapphire or ruby that functions as a bearing for the gears of an analog watch. The number of jewels in a watch determines its precision and quality

keeper
The loop on a leather watch strap that secures its end in place after the buckle has been fastened

kinetic
See automatic

LCD
The liquid crystal display on which the time and other features of a digital watch appear

lug
The projection on each side of a watch's case to which the watch strap or bracelet is attached

mechanical
A watch whose movement is based on the vibrations of a mainspring that is wound by hand or automatically, by the movement of the wearer

minute repeater
A complication that allows a watch to strike the time in hours, quarters or seconds by means of a push piece control on the side of its case

moon phase
A complication that allows a watch to indicate the current phase of the moon through an aperture on its dial

movement
The inner mechanisms of a watch that allow it to keep time. The movement of a watch may be quartz or mechanical

perpetual calendar
A complication that automatically adjusts a watch's calendar to accommodate leap years and months with different lengths

quartz
A watch whose movement is based on the vibrations of a minute piece of crystal that can be activated by a battery or light

skeleton case
A watch with a transparent dial or caseback, allowing its movement to be viewed

solid state
A watch with no moving parts

spring bar
The telescoping metal pin that fixes a watch strap or bracelt to the lugs on the watch's case

subdial
A small dial on the face of the watch used in complications like a chronograph to record elapsed time or the date amongst other features

tachometer
A complication that measures the speed of the wearer's travel using a numeric scale on the bezel of a chronograph

tonneau
A watch with a barrel shaped case that has two convex sides

tourbillion
A complication in mechanical watches that eliminates any error in timekeeping that might be cause by shifts in location due to variations in gravity

water resistance
A measure of the durability of a watch when put into contact with water. Water resistance is measured in atmosphers (ATM), where one ATM is equal to 10 meters of water pressure or 1 bar