Bustamite: Gemstone Information

Usually massive, transparent pink bustamite (Ca,Mn2)Si3O9 occurs at Broken Hill, NSW, Australia. The hardness is 5.5–6.5, the SG about 3.3–3.4 and the RI  1.683,  1.698 and  1.701 with a birefringence of 0.018. Gem-quality bustamite is also found at Daghazeta in Tanzania.Bustamite can be confused with rhodonite from its colour and common occurrence, but the RIs are lower.