Rock Identifier
Tumbled serpentine (likely bowenite) (Serpentine-group minerals, chiefly antigorite/lizardite; commonly Mg₃Si₂O₅(OH)₄) — metamorphic
metamorphic

Tumbled serpentine (likely bowenite)

Serpentine-group minerals, chiefly antigorite/lizardite; commonly Mg₃Si₂O₅(OH)₄

AI-generated identification · may be incorrect

Green, mottled black-and-white, waxy to greasy luster, opaque, and smoothly tumbled; hardness about 2.5–4 Mohs, with poor cleavage and massive structure. The dark patches may be magnetite, chromite, or other accessory minerals.

Identified More metamorphic
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Physical properties

Green, mottled black-and-white, waxy to greasy luster, opaque, and smoothly tumbled; hardness about 2.5–4 Mohs, with poor cleavage and massive structure. The dark patches may be magnetite, chromite, or other accessory minerals.

Formation & geological history

Forms when ultramafic rocks such as peridotite undergo hydration and metamorphism, commonly in ophiolites and subduction-related terrains. Serpentinization ranges from ancient Precambrian to modern geological settings.

Uses & applications

Used as a decorative stone, cabochon, carving material, and low-cost jewelry; some varieties are sold as “New Jade.” It is not true jade and is generally unsuitable for heavy-wear rings.

Geological facts

Serpentine is a mineral group rather than a single mineral, and its color commonly reflects iron and accessory minerals. Fibrous chrysotile is an asbestos form, though compact tumbled material is typically nonfibrous.

Field identification & locations

Likely serpentine if it feels relatively soft, has a waxy surface, and shows green mottling; it should scratch with a steel knife more readily than jade. Common sources include California, New Zealand, Italy, Canada, and Zimbabwe.