Danburite is not widely known, but its an excellent gem. With a hardness of 7 and an RI that ranges from 1.627 to 1.639, it cuts beautiful stones have excellent brilliance and flash. This gem was cut for me from material sourced from Mexico, where some of the best clear Danburite can be found. It’s 10.17 carats and measures 14.55 x 10.90 x 9.55 mm. Like most colorless gemstones, it’s difficult to photograph; the black you see in the gem is reflections of my camera. In the hand its much more brilliant than the photo can convey.