Brucite

Brucite is a soft, white-to-pale-green mineral made of magnesium hydroxide (Mg(OH)₂). It commonly forms in serpentinite and other magnesium-rich rocks and is closely associated with chrysotile asbestos, which has a layered structure built in part from brucite-like sheets.

Origin

Brucite was named in 1824 by François Sulpice Beudant in honor of the American mineralogist Archibald Bruce, who first described the mineral from a specimen found in Hoboken, New Jersey. It has since been recognized as a widespread accessory mineral in serpentinized ultramafic rocks worldwide.

Significance in Asbestos Context

Brucite matters in asbestos cases because its structure is one of the two alternating layers that make up a chrysotile fiber. The curling of these brucite-like sheets against silicate sheets is what gives chrysotile its tube-like shape. When experts analyze tissue samples or product samples, the presence and chemistry of brucite-like layers help confirm chrysotile identification and can sometimes point to the geologic source of the asbestos. Brucite itself is also found alongside chrysotile in mined ore, so its presence in a product or dust sample can support claims about the origin of contamination, particularly from serpentine-hosted deposits such as those in Quebec, California, or Italy.

Example Sentence

The mineralogist's report noted brucite intergrown with chrysotile in the insulation debris, consistent with ore sourced from a serpentinite deposit.

Related Terms

Chrysotile, Serpentine, Serpentinite, Provenance Analysis, Transmission Electron Microscopy, Magnesium Silicate

Notes

• If your case involves chrysotile exposure, ask whether your expert's fiber analysis includes electron diffraction or EDS data confirming the brucite-layer chemistry of identified fibers.
• Preserve any product samples, dust samples, or pathology blocks. Provenance work that ties brucite-bearing chrysotile to a specific mine or product depends on having physical material to test.
• Defense experts sometimes argue chrysotile fibers dissolve quickly in the lung because the brucite layer is acid-soluble; ask your legal team whether expert testimony rebutting this 'biopersistence' argument is part of your case.