Rock Identifier
Likely serpentine or weathered greenstone pebble (Serpentine-group minerals, chiefly antigorite/lizardite; possibly chlorite–actinolite greenstone) — metamorphic
metamorphic

Likely serpentine or weathered greenstone pebble

Serpentine-group minerals, chiefly antigorite/lizardite; possibly chlorite–actinolite greenstone

AI-generated identification · may be incorrect

Pale gray-green, mottled, dull to waxy luster, fine-grained and rounded by abrasion; typical hardness is about Mohs 2.5–4, with no visible cleavage. The image is insufficient for reliable mineral identification or specific gravity.

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Physical properties

Pale gray-green, mottled, dull to waxy luster, fine-grained and rounded by abrasion; typical hardness is about Mohs 2.5–4, with no visible cleavage. The image is insufficient for reliable mineral identification or specific gravity.

Formation & geological history

Likely formed by low- to moderate-grade metamorphism or hydration of ultramafic rocks, commonly during ancient tectonic activity; the pebble’s exact age and provenance cannot be determined visually.

Uses & applications

Small specimens are used for teaching and collecting; attractive serpentine may be carved or polished as ornamental stone, while greenstone can serve as minor landscaping material.

Geological facts

Serpentine is not one mineral but a group of hydrated magnesium silicates, commonly produced when olivine- and pyroxene-rich rocks react with water.

Field identification & locations

Look for a distinctly green color, waxy surface, softness, and possible fibrous texture; a streak, hardness test, and magnification are needed. Common sources include California, Italy, New Zealand, and metamorphic belts worldwide.