20 Terms
Contributors in Gemstones
Gemstones
Diamond cut
Fashion; General jewelry
Also known as the Brilliant Cut, the style of cutting a stone with multiple facets to maximise brilliance. Modern round brilliant cuts have 58 facets.
Dichroism
Fashion; General jewelry
Term meaning the ability of some gems to display a second shade of the same colour when viewed from a different angle. A dichroscope can see this change, and is used for identifying certain stone.
Diffusion treatment
Fashion; General jewelry
Form of heat treatment that adds one or more chemicals to the heating process to change the colour of a gemstone. Typically the treatment does not penetrate deep into the stone, so gems treated in ...
Dispersion
Fashion; General jewelry
He property of a transparent stone to split light into the seven spectral colors, causing the "fire" which is refracted by the internal facets. Diamond has a very high dispersion, hence its high ...
Fissure
Fashion; General jewelry
Surface crack on a gemstone. Gems with fissures may be Fracture Filled.
Fluorescence
Fashion; General jewelry
He ability of some gems to appear a different colour when viewed under ultraviolet light. If or not a stone has fluorescence is a valuable aid in gem identification.
Fracture filling
Fashion; General jewelry
Mall cracks or fissures in a gemstone can interrupt the flow of light through the stone, creating white or "dead" spots in the colour of the stone. Sometimes these fractures will be filled with ...
