Serpentine Jade (New Jade/Olive Jade)

Hardness: 2.5-5.5 (Mohs scale), generally softer than true jade. Color: Light green to yellowish-green (often referred to as 'apple green' or 'olive green'). Luster: Greasy, waxy, silky, or dull. Crystal Structure: Monoclinic (for most serpentine minerals like antigorite and lizardite), microcrystalline aggregates. Cleavage: Variable, often splintery fracture. Specific Gravity: 2.5-2.6.

Serpentine forms from the alteration of ultramafic igneous rocks (rich in magnesium and iron), such as peridotite and dunite, through a process called serpentinization. This occurs when these rocks react with water at low temperatures and high pressures, typically along subduction zones or mid-ocean ridges. The process involves hydration and metamorphic recrystallization. Its geological age varies widely depending on the original ultramafic rock and the timing of the metamorphic event.

Commonly used in jewelry as beads, cabochons, and carvings, often as a more affordable alternative to true jade (nephrite or jadeite). Also used for ornamental objects, architectural decoration (as serpentinite rock), and sometimes for industrial purposes like an asbestos substitute (though caution is needed due to potential health risks with certain serpentine varieties containing asbestos fibers).

Serpentine is not true jade, but is often marketed as 'New Jade', 'Olive Jade', 'Serpentine Jade', or 'Korean Jade' due to its similar appearance. True jade is either nephrite or jadeite, which are significantly harder and more durable. The 'serpentine' group of minerals includes antigorite, chrysotile, and lizardite. Chrysotile is the fibrous form of serpentine and is a type of asbestos.

Can be identified in the field by its characteristic greasy or waxy luster, relatively soft feel (can be scratched by a knife in many cases), and shades of green. It often has a mottled or veined appearance. Common locations include metamorphic belts worldwide, particularly in areas where oceanic crust has been subducted or obducted. Major sources include China, Korea, New Zealand, Afghanistan, and the United States (e.g., California). Tips for collectors: Be aware that 'New Jade' is serpentine, not true jade. A scratch test can help distinguish it from harder minerals. The label "岫玉" (Xiù yù) on the tag typically refers to Serpentine Jade from Xiuyan, Liaoning Province, China.