Wood-like Amianthus, or Asbestus Enlarge
May 1. 1805. Publiſhed by Ja.s Sowerby. London.
British Mineralogy
CXXIV
Silex magnesiatus; var. amianthiformis

Wood-like Amianthus, or Asbestus

  • Class 2. Earths.
  • Order 1. Homogeneous.
  • Gen. 4. Silex.
  • Spec. Magnesiatus.
  • Div. 2. Imitative.
  • Spec. Char. Silex in combination with Magnesia.
  • Syn.
    • Amianth. Kirw. v. 1. 161. Emmerl. 1. 402. Jameson, 1. 442. Wern.
    • Asbestus maturus, Amaianthus. Waller, 1. 408. 410.
    • Asbeste. Haüy, 3. 245.

This is formed in upright and often curved filaments, sometimes in masses or plates. It is often indurated in a high degree, and resembles wood petrified—see the lower figure. The present kind is found at Portsoy in Scotland in great abundance and variety, crossing in many directions through the Serpentine rocks. The upper specimen was given me by Lord Seaforth. It is somewhat undulated, and varies in colour; is harder in some parts, and softer in others. In some it may be separated into flocculi with the finger nail, and in others it is so hard as to bear a good polish; when it is more brittle, and approaches Actinolite. The lower piece was lent me by my friend G. Laing, Esq.; it comes also from Portsoy, and is remarkable for filling a narrow flaw in the Serpentine in a very thin plate, and showing fractures transverse to the straiæ at nearly right angles. It is also very regular in hardness, so as to take a good polish all over the face; being about the hardness of common marble. This, and many earthy substances, resemble wood, especially the undulating slaty or irregularly schistiform rocks.

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