Sphalerite

Sphalerite occurs in many colors, including green, yellow, orange, brown, and red. Many different trace elements — such as copper, tin, and iron — can contribute to its color, and streak testing a sphalerite may result in either a yellow, pale brown, or white streak. Sphalerite rough and cut set, Camp Bird Mine, near Ouray, Ouray County, Colorado, USA. 2.8 x 2.5 x 1.8 cm (specimen); 10.54 mm, 5.40 carats (round brilliant-cut gem). © Rob Lavinsky, www.iRocks.com. Used with permission.

Article: Destructive Gemstone Tests: Streak Testing

Credit: www.iRocks.com