Diamond Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Appraisal: A written estimate of the approximate retail value of the item. Appraisals can be used for insurance purposes and should be updated every few years due to changes in market price.

B

Baguette: A step cut in the shape of a small rectangular stone.

Bezel facet: A facet on the Crown or the upper part of the diamond above the girdle. On a round diamond these are 8 large kite shaped facets on the crown.

Blemish: A surface imperfection external to the diamond. For example a nick, scratch or poor polish on a diamond.

Brilliance: Described the reflections of light coming from the diamond to the eye as a result of internal and external reflections.

Brilliant Cut: The most common style of diamond cutting, consisting of a combination of triangular and kite shaped facets. Round diamonds have 58 facets and are the most brilliant diamond shape.

Bow Tie Effect: Caused by a shadowy area visible in some fancy shaped diamonds, caused by light leaking out of the bottom of the diamond.

Butterfly : The earrings back or closure that goes over the post an earring to secure to the earlobe.

C

Carat: the standard measurement of weight of a diamond. One carat equals 100 points or .20 of a gram. The more a stone weighs the more the diamond is worth if all other factors are equal.

Cavity: A type of inclusion consisting of a large deep opening in the stone.

Certificate: A document produced by a gemological institute describing the diamond’s characteristics.

Clarity: The degree to which a diamond is free from any blemishes or inclusions. The clarity grading scale ranges from flawless (IF) to imperfect (I). The size, number, position and colour of the inclusions determine the clarity. Flawless diamonds are the most valuable and hence the most expensive.

Cleavage: A break in a diamond caused by a crystalline mineral to break in certain definite directions. May be caused by internal pressure or a sharp blow.

Cloud: A cluster of tiny white inclusions giving a “milky” or “cloud” appearance.

Colour: One of the four value factors of a diamond. Colour range involves determining how close the stone is too colourless. Diamond colour is ranked from D (colourless) to Z (brown). Coloured diamonds (blue, pink,. green, etc) are ranked on a different scale.

Crown: The upper part of the diamond that is above the girdle. Consisting of a large flat area on top called the table and facets below it.

Culet: The smallest facet at the bottom of the diamond. Some diamonds do not possess culets.

Cut: The proportions and finish of a polished diamond given to the diamond by the cutter. Describes the size and angle relationships between the facets and different parts of the stone. Cut determines the overall beauty of the diamond.

D

Diamond: A mineral that crystallised in the cubic system and is composed of carbon.

Depth: The distance between the table and the culet measured in millimetres.

Depth Percentage: The depth of the diamond divided by the average width.

Dispersion: The separation of white light as it separates into colours.

Durability: The hardness, toughness and stability that describes the diamonds ability not to wear.

E

Emerald Cut: A diamond shape usually rectangular with cut corners.

F

Facet: A plane, polished surface of the diamond.

Feather: A fracture in a diamond that looks like a white feather.

Fire: Flashes of colours seen in gemstones as a result of dispersion.

Flaw: An imperfection in the diamond.

Fluorescence: Fluorescence means that a diamond will glow usually in blue under UV light when illuminated. The effect is like a white shirt at a disco party, it glows. Fluorescence can range from faint to very strong and can make a yellowish diamond look white or colourless.

Four C’s: A diamond’s value characteristics, cut, colour, clarity and carat.

Fracture: A crack on the diamond’s surface that is not in the direction of a cleavage plane.

G

Girdle: The outer edge or the widest part of the stone where a narrow band is formed around it.

Grading Report: Also called a certificate, issued by an independent laboratory which accurately describes the characteristics of the diamond. For example GIA and EGL.

GIA: Gemological Institute of America, the worlds foremost educational authority on diamonds. GIA provides the most trustworthy and accurate diamond grading report in the world.

H

Hearts and Arrows: Diamonds with a complete pattern of hearts and arrows achieved by perfect cutting proportions.

I

Inclusions: A natural imperfection in a diamond. Common inclusions are: feather, clouds, crystals.

Invisible Setting: A setting used traditionally used with princess diamonds, where no metal is shown. The diamonds are closely locked together with special grooves made in the sides of the diamonds. Usually used in multiple rows giving the appearance that the diamonds are set invisibly.

K

Karat: Used to state how much pure gold is found in a item. 24K is pure gold, 18K is 18 parts gold and 6 parts other metals, 14K is 14 parts pure gold and 10 parts other metals etc.

L

Laser Identification: A small laser inscription on a diamond for identification. Can be the diamond certificate number, a message, brand name, etc.

Loupe: Small magnifying lens used to examine diamonds.

Level-Backed: An earrings which has backing that folds and latches behind the ear, used for drop earrings.

M

Marquise: A fancy diamond shape with the girdle outline in an elliptical shape with pointed ends.

Melee: A term used to describe small diamond under .20 carats.

Mounting: When a diamond is set into a setting.

N

Natural: The portion of the rough diamond remaining after the cutter has polished and faceted the diamond.

Nick: A minor chip on the diamonds’ surface.

O

Oval: A fancy shape diamond with the girdle outline in an oval shape.

Omega catch: A clip that goes over the post to give pierced earrings a more secure fit.

P

Pave: A style of setting where small stones are positioned within close proximity in two or more rows.

Pavilion: The bottom part of the diamond , below the girdle.

Pear Shape: A fancy shaped diamond in the shape of a pear.

Pinpoints: Extremely small inclusions in a diamond.

Point: A measurement of the diamond, 100 points is equal to 1 carat.

Polish: The way a cutter finishes the facets on a diamond. The smoothness of the surface of the diamond.

R

Rough: Any uncut or unpolished diamond.

Round Brilliant Cut: The most common diamond shape, containing 58 facets.

S

Scratch: A linear nick seen as a fine white line, curved or straight.

Simulated Stone: Any artificial diamond like material marketed as a look-alike diamond.

Solitaire: A ring containing a single diamond.

Symmetry: Rated from poor to excellent, based on a diamond’s proportions and the relation of one facet to another.

Screw Back: An earrings backing that screws onto a threaded earrings post, usually used with diamond stud earrings for added protection against loss.

T

Table: The largest facet which sits on top of the diamond. The table is where most of the light enters and exits a diamond.

Table Percentage: Comparison of the size of the table facet to the width of the stone at the girdle. The width of the table divided by the average diametre.

Tone: A characteristic of colour that determines the stones lightness or darkness of shading.

Transparency: The ability of the diamond to transmit light.

Trillion: Triangular shaped diamond; possesses an arched shaped triangle cut with 25 facets on the crown and 19 facets on the pavilion.

U

Ultrasonic cleaner: Will clean any piece of jewellery that can be soaked in a liquid within minutes. They are comprised of a metal cup, which you fill with water and detergent. When the machine is turned on, a high-frequency turbulence is created.

Ultra Violet Light: Light that is invisible to the naked eye due its short wavelengths.

V

VVS-1: Very Very Slightly Included 1: Usually just one tiny inclusion is visible only to a trained eye under 10x magnification. These are exceptional quality diamonds and relatively expensive.

VVS-2: Very Very Slightly Included 2: Tiny inclusions are visible only to a trained eye under 10x magnification. These are outstanding quality diamonds and relatively expensive.

VS-1: Very Slightly Included 1: Very small inclusions are visible with 10x magnification. These are high quality diamonds and moderately expensive.

VS-2: Very Slightly Included 2: Several very small inclusions are visible with 10x magnification. These are quality diamonds and moderately expensive.

W

White gold: An alloy of yellow gold that contains silver, zinc, rhodium or platinum as a whitening agent.

Y

Yellow gold: The natural colour of pure gold.

Z

Zirconia: A pure metal synthesised in crystal form, cubic zirconia, is used as a simulant.