Tourmaline quartz is a rock crystal (or hyaline quartz) that has black tourmaline inclusions in the form of "threads" that cross it, hence the name "tourmaline". Quartz has been known and appreciated since prehistoric times because it is easily available and suitable for use as a tool thanks to its hardness. The oldest name, reported in Greek by Theophrastus in the fourth century. to. C, is “krýstallos”, which means ice. For Pliny, a Latin author of the first century. d. C, the "crystallus" is "ice frozen beyond all limits". Quartz is one of the most prevalent minerals in the earth's crust and is a significant component of many types of igneous, metamorphic and sedimentary rocks. Tourmalines are a group of minerals belonging to the class of silicates, order of cyclosilicates. The name derives from the Sinhalese turmali which literally means mixed pack or stone of various colors. The crystal belongs to the trigonal system, is prismatic, very elongated, vertically striated and sometimes with unequal development at the two ends of the vertical axis. In black tourmaline the color is given by the presence of iron inside.
Dimensions
Height (cm): 7.8
Depth (cm): 2.2
Width (cm): 2.6
Weight (g): 72
Property
Chemical formula: SiO2
Mohs scale: 7
Relative Density: 2.65
Crystal System: Trigonal
