Antigorite

Antigorite is a serpentine mineral closely related to chrysotile (the form of asbestos used in most commercial products), but it usually forms in flat, plate-like or corrugated sheets rather than long flexible fibers. It is generally not regulated as asbestos, though it can occasionally grow in fibrous habits that raise health questions. Antigorite is common in serpentinite rocks and is often found alongside chrysotile and tremolite.

Origin

Named in 1840 by mineralogist Eduard Schweizer after the Antigorio Valley in the Italian Alps, where the mineral was first described. It is one of three main serpentine polymorphs, along with chrysotile and lizardite.

Significance in Asbestos Context

When laboratories analyze lung tissue, dust samples, or product materials, distinguishing antigorite from chrysotile matters because only chrysotile (and certain fibrous amphiboles) are regulated asbestos. Defendants sometimes argue that fibers found in a product or in tissue are non-asbestiform antigorite rather than chrysotile, which can affect whether an exposure is considered asbestos exposure at all. However, antigorite frequently occurs in rocks mined for chrysotile and talc, and its presence can be a marker that a material came from a serpentinite source where chrysotile contamination is likely. Your experts may need to address fiber identification methods (such as transmission electron microscopy with selected area electron diffraction) to confirm exactly which serpentine mineral is present.

Example Sentence

The defense expert claimed the fibers recovered from the talc were antigorite rather than chrysotile, but the plaintiff's mineralogist used electron diffraction to confirm true asbestiform chrysotile was present.

Related Terms

Chrysotile, Lizardite, Serpentine, Tremolite, Asbestiform, Transmission Electron Microscopy

Notes

• If a defense expert characterizes fibers in your case as "antigorite" or "non-asbestiform serpentine," ask your legal team whether an independent mineralogist has reviewed the same samples using electron diffraction or similar definitive methods.
• Preserve any laboratory reports, fiber analyses, or product testing results that identify serpentine minerals. The specific mineral name matters.
• Antigorite frequently coexists with chrysotile in serpentinite deposits, so its identification in a product can support provenance arguments about where the raw material was sourced.