348 Glossary
First Bye. (First By-water.) Diamond exhibiting a faint greenish tinge.
First Water. Diamonds so pure and colourless that they can scarcely be distinguished from water when immersed in it.
Fish-Eye. A diamond cut too thin to present the maximum effect of brilliancy.
Flat Ends. Thin cleavages from the faces of a diamond crystal.
Flats. Thin, flat pieces of diamond crystal.
Flaw. A crack, defect, fault, fissure, or other structural imperfection in a gem.
Fluorescence. The
phenomenal quality exhibited by some gems of showing one colour in
transmitted light and another in reflected light; fluorite, from which
the word is derived, is a striking example.
Flux. To melt, to fuse. As a noun, a fluid or substance which may be used to fuse some other material.
Fracture. Breaking a gem otherwise than the lines of cleavage.
Gem Colour. The most desirable colour for a stone.
Gemology. A word coined to supply a specific name for the science of gems.
Glassies. Octahedral diamond crystals (transparent).
Glassy. Applied to diamonds which lack brilliancy.
Golconda. Ancient
and famous group of diamond mines on the Kistna River, India, where
were found the Koh-i-noor and other world-famous diamonds.
Golcondas. Diamonds from India.
Grain Marks. Lines on the facet surfaces, the result of imperfect polishing.
Grainers. Diamonds
which in weight will correspond to fourths of a carat; a diamond
weighing one half a carat is a two-grainer; one weighing three quarters
is a three-grainer ; a diamond of one carat in weight is a four-grainer.
Granitic. Like, or of, granite.
Granular. Composed of or resembling granules or grains.
Harlequin. Most beautiful variety of opal.
