Could it be that your customer is referring to Hawk’s Eye, also
called Falcon’s Eye? It seems plausible, the three share strong
symbolistic/metaphysical/tribal ties. Did your customer describe the
stone at all?
Hawk/Falcon’s Eye is listed in GIA’s Gem Reference Guide - a superb
resource containing that’s not commonly found. Here’s a
quick rundown on the hard facts: it is actually a variety of tiger’s
eye, semi-translucent to opaque, grayish blue in color, 7 on Moh’s,
SG 2.64-2.71, risky to steam, “usually” safe in ultrasonics, soapy
water is okay. The color can be natural OR dyed so you may want to
inquire about particular stones & inspect for signs of dye
Personally, I’ve only seen one - a high domed, 16x12mm (est) oval
cabochon bezel-set widthwise in a simple 18k yellow estate ring that
a Belgian dealer had for sale a la Internet last spring. The unusual
stone and timeless mounting fascinated me enough to buy it - glad I
did, I wear it all the time (with care of course).
All I’ve found out is that it’s not a highly valuable stone but it is
very hard to find naturally bluish. The rarity isn’t reflected in the
pricing because so few people know of it, there’s just no demand. I
never stumbled on it in Tucson but never looked, either! GJX would
probably be prime hunting ground for Hawk/Falcon’s Eye since the
selection there is so diverse.
My stone was confirmed natural in color by a GG. I think it’s
prettier than what comes to mind for ‘‘grayish blue’’, I’d describe
it as medium to dark blue in body color but it looks vastly different
under various lighting conditions. Sometimes the color appears fairly
solid with a single thin, white cat’s eye running lengthwise through
the center. Other times the stone looks more or less like a blue
Tiger, revealing patterns and play of light in cornflower to navy
If you’d like a less-than ideal jpg, email me directly and I’ll try
scanning my ring for you. Might be helpful in confirming your
customer’s desired stone ID and/or your scouting missions.