In the 2007 I was lucky to acquire few pieces of an interesting rough of yellow danburite , I cut 3 pieces cabochon with sharp cat’s eye effect and few facet stones were cut from a friend of mine. See the article on Rivista Gemmologica Italiana Vol.2 n°3 2007. Previously this stone was know from Myanmar and Madagascar, now some material has been excavated in Morogoro area ,Tanzania. Most of the rough is heavy fractured and a very small percentage of gem quality may be obtained.( on one ton of rough less than 200 cts. were obtained). For more information about this beautiful gem, read Gems & Gemology at pag.170 Summer edition.
The hardness is 7. to 7.5