Jade (Nephrite or Jadeite)

Hardness: Nephrite 6-6.5, Jadeite 6.5-7 (Mohs scale). Color: Typically green (light to dark, often mottled or banded), but can also be white, gray, lavender, yellow, orange, or brown. Luster: Vitreous to greasy. Crystal structure: Nephrite has a felted, interlocking fibrous structure; Jadeite has a tough, interlocking granular structure. Both lack distinct cleavage due to their tough interwoven structures. Specific gravity: Nephrite ~2.9-3.0, Jadeite ~3.3-3.5.

Both Nephrite and Jadeite form under conditions of regional or contact metamorphism. Nephrite forms in serpentinite (metamorphosed ultramafic rocks) or dolomitic marbles at relatively low temperature and high pressure. Jadeite forms under conditions of high pressure and relatively low temperature, typically in subduction zones within serpentinites or blueschist facies metamorphic rocks. Their geological age varies depending on the specific geological events and locations where they formed.

Primarily used for carved ornamental objects, jewelry (beads, pendants, rings), and sculptures due to its exceptional toughness and beautiful range of colors. Historically, it has been used for tools and weapons due to its durability. Culturally, especially in China and other East Asian countries, jade holds deep symbolic meaning and is highly valued.

Jade is actually two distinct mineral species: Nephrite and Jadeite. While they are visually similar and were traditionally both called 'jade,' they have different chemical compositions and slightly different physical properties. Jadeite is generally rarer and considered more valuable, especially the vibrant emerald-green variety known as 'Imperial Jade' from Myanmar (Burma). It is renowned for its incredible toughness, which allowed ancient civilizations to carve intricate objects without the material fracturing easily.

In the field, distinguishing true jade from simulants can be challenging without specialized tools. However, key identifiers include its typical green to white color, waxy to greasy luster, and cold, dense feel in the hand due to its relatively high specific gravity. When buying, look for even color, good translucency (especially for jadeite), and lack of significant cracks or inclusions. Common sources include Myanmar (Jadeite), China, New Zealand, Siberia, Canada (British Columbia), and the United States (California, Wyoming). For the beads shown, the varying shades of green and mottled appearance are common in jade, suggesting a natural origin. The absence of noticeable cleavage planes and a 'waxy' appearance can also be indicative.