Editing Demantoid (section)

==Appearance==
{{unreferenced section|date=August 2011}}
Demantoid is the green variety of andradite garnet,<ref>C. Ghisoli, and F. Caucia, "[http://www.gia.edu/research-resources/gems-gemology/issues/spring2011-contents/SP11AB.pdf A contribution to the study of FTIR spectra of opals]" (abstract), ''Gems & Gemology'' (Spring 2011), Gemological Institute of America</ref> so demantoids are always primarily green (by definition), but the exact shade ranges from a very strong yellowish green to nearly the color of a fine [[emerald]]. Some stones have a brownish cast, which is due to iron. Its dispersion (0.057) is unusually high, and this is often visible as "fire" (rainbow-coloured flashes of light), although in some cases the stone's green body colour can render this effect less noticeable. Their luster is [[adamantine lustre|adamantine]]. Demantoid also has a high [[refractive index]] of 1.80 to 1.89.

Demantoids are generally small, with finished stones generally under {{convert|1|carat|mg}}  and stones over {{convert|2|carat|mg}} are rare.  Stones over {{convert|3|carat|mg}} are very rare.

Stones with more intense green coloration are generally highly valued, but lighter stones of yellowish green display substantially more fire.  The choice of stone color or fire can therefore be a matter of personal preference, with some preferring the more yellowish-green stones to the green stones.