ZIRCON
Zircon is a wonderful gem that comes in a variety of colors including Red,
Reddish-Brown, Yellow, Gray, Green, and Blue.  It is highly dispersive (close to a diamond - clear Zircons are a close match), and it is also doubly refractive making the gem look like it has twice as many facets than are actually cut.  The RI is also very high (also similar to diamond) making for a very sparkling gem. Zircon has almost the perfect set of attributes for any gem. The hardness is also perfect for jewelry except that Zircon is brittle, which is the only draw back if for a ring stone.  Rings must be treated with care as the edges may be easily chipped if struck. A protective mounting is advised.  Fine Zircon is often confused with "zirconia" which is synthetic and of little value.  The unfortunate naming of the synthetic material has caused natural/real Zircon to be quite underrated and misunderstood. But this misunderstanding has helped to keep down the prices of these super gems. (This may not always be the case.)
Sorry, SOLD

ORIGIN: Mined in Tanzania, Faceted in USA
CUT: 16-Sided Round Brilliant cut
COLOR: Dark Cherry Red
INCLUSIONS: Eye Clean, Clean under 10X  loupe, minor included crystals under 10X 'scope. Very Nice !
OTHER INFO: Pure Red Zircon is fairly difficult to find.  The pic below is under diffused natural lighting.  Gem is brilliant under direct lighting (and hard to photograph).
GIA GG lab appraisal at $100/ct ($71.00)