Tourmaline, Schorl cluster - Minas Gerais, Brazil (MS2902a)

Discrete Tourmaline crystals have inter-grown into a large hand-sized specimen weighing about 190 grams (near a half-pound) and measuring about 65mm x 50 mm x 30mm.  Other minerals, such as feldspars add contrasting color.  The yellow cube is a typical bouillon cube of about a half-inch on a side, photographed for size reference.