Jade

Hardness: 7 on the Mohs scale. Color: Green, often with banding or mottling of various green shades, sometimes with white, yellow, or brown inclusions. Luster: Vitreous to waxy. Crystal Structure: Trigonal. Cleavage: None. Specific Gravity: 2.58-2.64.

Jadeite forms in high-pressure, low-temperature metamorphic environments, typically in subduction zones. Nephrite forms in regional metamorphic environments associated with serpentinization of ultramafic rocks. Both can be found in alluvial deposits where they have been eroded from their original formation sites. The geological age of jade deposits can vary widely, from hundreds of millions of years to much younger formations.

Jade is primarily used as a gemstone and for ornamental carvings. It's highly valued in jewelry, sculptures, and decorative objects. Historically, it was also used for tools and weapons due to its toughness.

Jade has been prized for millennia in many cultures, particularly in East Asia and Mesoamerica, where it was often considered more valuable than gold. It's often associated with good luck, purity, and longevity. The term 'jade' can actually refer to two distinct minerals: nephrite and jadeite, which have different chemical compositions and slightly different physical properties. What is shown in the image is likely a tumbled and polished piece of jade that exhibits its characteristic waxy luster and varied green coloration.

To identify jade in the field, look for its characteristic waxy to vitreous luster and toughness. It's difficult to scratch with a knife (Mohs 6-7). Jade often occurs in nodules or boulders within riverbeds, or as veins within host rocks. Common locations include Myanmar (jadeite), New Zealand, Canada, China, Russia, and the United States (nephrite). For collectors, identifying the type of jade (nephrite vs. jadeite) is important for value, as jadeite is generally rarer and more valuable. Look for its distinctive greasy feel when unpolished and its translucent to opaque nature.