WHAT IS A GEM RUBY?
MINERAL SPECIES: Corundum. APPEARANCE: Best color = Vivid red, not too dark and not too light, without overtone of brownish (best under incandescent light). Popular expression for the best color = Pigeon-blood red. Dichroism = Strong, purplish red and orangey red. Fluorescence = Strong and pleasant for Rubies with low iron content. Transparency = Transparent (if not too much included). Clarity = Inclusions are accepted to a certain extent and partly reflect the quality and price of a Ruby. Brilliancy = High; may be covered by a too strong color saturation or too many inclusions. Phenomena = Asterism; Star Ruby (semitransparent; lower part of the cabochon cut is kept unpolished). FACET CUTS: Cushion cut = A premium is often add to this ideal cut for a Ruby. Oval = Ideal and most common shape for Rubies. Pear shape, heart shape and marquise cut = Fancy cuts reach slightly lower prices. Rounds and squares = Rare in sizes over 6 mm. Emerald cut = Very rare and fetch premium prices because
