Tremolite

TREMOLITE (var. NEPHRITE, JADE)

HISTORY, NAME, LOCALITIES: The nephrite, pronounced NEH-frite, variety of tremolite has been known since ancient times.  Its name, assigned in 1794, stems from the Greek nephros, meaning “kidney” and alluding to the stone’s purported ability to alleviate renal disorders.  Nephrite is collected in China, Russia, New Zealand, Canada, and the United States (Wyoming, Alaska).

MINERALOGY, PROPERTIES, OCCURRENCE: The nephrite variety of tremolite [basic calcium magnesium silicate, Ca2MgSi8O22(OH)2] crystallizes in the monoclinic system and occurs as tough, compacted masses of tiny, interlocked, bladed crystals.  It has a hardness of Mohs 5.0-6.0, an uneven fracture, a vitreous-to-silky luster, and a specific gravity of 2.9-3.1.  Nephrite is opaque to semitransparent, with colors ranging from white and yellow to green and dark gray.  It is an amphibole mineral that occurs primarily in contact metamorphic rocks.

METAPHYSICAL PROPERTIES, LORE, USES: With its substantial toughness and durability, ancient stoneworkers fashioned nephrite into ax heads, knives, and spear points.  Chinese carvers fashioned intricate, complex objects of great beauty and value from nephrite.  Green, translucent nephrite is a type of jade that is a valuable gemstone that is fashioned into cabochons and small decorative objects.  Jadeite [sodium aluminum iron silicate, Na(Al,Fe)Si2O6] is also a form of jade.  According to metaphysical beliefs, nephrite is a protective stone that converts negative energies into positive energies, instills a sense of calm and well-being, and helps to increase the enjoyment of life.

COLLECTORS’ INFORMATION: Translucent nephrite in pleasing colors, notably waterworn pieces from beaches or semi-polished pieces from alluvial deposits, is valued by collectors.