Asterism -  The star effect displayed by some stones when cut as a cabochon.

Blemish - Surface characteristics such as scratches, nicks, chips and abrasions which can almost Always be removed by re-polishing or re-cutting the stone.

Cabochon - A cutting style in which the upper portion of the stone is fashioned into a polished dome and the bottom is usually flat or rounded.

Carat - Unit of weight used for weighing gems; equivalent to one fifth of a gram.

Cleavage - The breaking or splitting of a stone along lines of weakness related to the stones internal atomic structure.

Crown - The top portion of a cut stone which lies above the girdle.

Culet - A small polished facet at the bottom of a stone where the pavilion terminates.

Doublet - A stone comprised of two separate pieces which have been cemented of fused together.

Feather - A visible fracture within the stone. Usually has a feathery appearance.

Fire - The splitting of white light as it passes through the gemstone, creating the colors of the rainbow. 

Girdle - The band around the widest part of a cut stone. The area where the crown meets the pavilion.

Hardness - The stone's ability to resist scratching. Refer to MOHS Hardness Scale

Inclusions - Irregularities within a stone such as markings or foreign particles trapped within a stone during its formation.

Lapidary - A craftsman who is skilled in the cutting and polishing of gemstones.

Natural Gemstone - A gemstone which was formed in nature over a period of time without human assistance.

Opaque - Not allowing light to pass through.

Organic Gem - A gem made by or derived from living organisms. (Example---pearls, coral).

Pavilion - The lower portion of a cut stone which lies below the girdle.

Pennyweight - Also known as DWT - 24 grains, 0.05 ounces, 1.555 Grams

Rough - The term used to describe a gemstone, rock or crystal that is still in its natural state, before cutting and polishing.

Specific Gravity - Density, measured as the weight of the material compared with that of an equal volume of water.

Stability - Refers to a stone's response to heat, temperature changes, light, radiation and chemicals.

Step Cut - Rectangular Table Facet and girdle, with rectangular facets parallel to these.

Table - The central facet on a gemstones crown.

Three Phase Inclusions - An inclusion made up of 3 components; gas bubble and a solid crystal trapped in a liquid.

Toughness - The stone's resistance to breaking, chipping or cracking.

Translucent - Cannot see through clearly, but allows light to pass through.

Transparent - Allows light to pass through and can be seen through clearly.

Triplet - A stone comprised of three separate pieces which have been cemented or fused together.

Two Phase Inclusion - An inclusion made up of 2 components; gas bubble trapped in a liquid.

Zoning  - Areas of slightly or strikingly different colors or hues or color saturation caused by changes in chemical composition that takes place during the formation of a stone.

WEBSITE  / PAGE Copyright 2006 - 2008. ORIONS GEMZ AND JEWELRY - ALL RIGHTS RESERVED

CONTACT INFORMATION / ORDERING INFORMATION