Serpentine Identification Guide

What Serpentine Looks Like

Serpentine is a group of magnesium silicate minerals (antigorite, lizardite, chrysotile) usually seen as green to yellow-green, olive, brownish, or blackish-green masses, often mottled or veined like snakeskin (hence the name). Luster ranges from greasy/waxy to silky (fibrous chrysotile) to dull; it is typically translucent to opaque. It feels slightly soapy or smooth to the touch. Massive serpentine carves easily and takes a soft polish, which is why it's widely sold as imitation jade.

Step-by-Step Field ID Checklist

1. Note the color and pattern — mottled green with paler veins; greasy sheen.
2. Test hardness — serpentine is soft (Mohs ~2.5–4) and a steel knife scratches it readily. This separates it from true jade.
3. Feel the surface — smooth, soapy, sometimes waxy.
4. Check for fibers — silky, splintery fibers indicate chrysotile (asbestos form — handle with care).
5. Look at the setting — associated with ultramafic/altered rocks.
6. Streak — white.

Key Diagnostic Tests

• Mohs hardness: ~2.5–4; scratched by a steel knife — the key separator from jade (jadeite ~6.5–7, nephrite ~6–6.5).
• Streak: white.
• Luster/feel: greasy to waxy, smooth/soapy touch.
• Density: ~2.5–2.6 g/cm³, lightish.
• Acid: essentially inert in dilute HCl (helps distinguish from carbonate look-alikes).
• Fibrous habit: chrysotile serpentine is the asbestos mineral — avoid grinding/inhaling dust.

Common Look-Alikes and How to Tell Them Apart

• Jade (jadeite/nephrite): the big one — serpentine is often sold as 'new jade' or 'Korean jade.' Jade is much harder (won't scratch with a knife) and tougher; serpentine scratches easily. Hardness is decisive.
• Bowenite (a hard serpentine): a denser, harder serpentine variety (~5–6) used as a jade substitute; still usually softer than true jade and confirmed by gemological testing.
• Soapstone (talc-rich): even softer (Mohs 1), scratched by a fingernail; serpentine is slightly harder.
• Epidote/green garnet: harder, scratch glass; serpentine does not.
• Malachite: banded green but fizzes in acid (carbonate); serpentine does not.

Where Serpentine Is Typically Found

Serpentine forms by hydrothermal alteration of ultramafic rocks (peridotite, dunite) and makes up serpentinite bodies along fault and subduction zones. Major occurrences include California (the state rock), the Alps, the Lizard Peninsula in England, Italy, China, and many ophiolite belts worldwide. It's commonly found in greenstone terrains and tectonic mélange zones.