African emerald

1. A deceiving name for green fluor; also for green tourmaline.
2. An emerald from the Transvaal. It is usually quite yellowish green; often dark and dull. Hardness, 7.5; sp gr, 2.72 to 2.79; refractive index, 1.58 to 1.59; birefringence, 0.007. Syn: Transvaal emerald
3. A term variously used for southern African emeralds (beryl), green tourmaline, and other green gemstones from this region.
   Source: Dictionary of Mining, Mineral, and Related Terms