Byssus-like Carbonate of Copper Enlarge
Oct.r 1. 1803. Publiſhed by Ja.s Sowerby. London.
British Mineralogy
XLVII
Cuprum carbonatum, var. byssoides

Byssus-like Carbonate of Copper

  • Class 3. Metals.
  • Order 1. Homogeneous.
  • Gen. 4. Copper.
  • Spec. 3. Carbonate of Copper.
  • Div. 2. Imitative.
  • Var. 8. Byssus-like.
  • Spec. Char. Copper combined with carbonic acid.
  • Syn.
    • Green Malachite. Rashleigh, fasc. 1. tab. 7. f. 6.
    • Cuivre Cabonatée vert soyeuse. Haüy 3. 573.
    • Malachit. Emmerl. t. 2. p. 253.

Malachite Copper ore of this beautiful Byssus-like appearance has been found in great abundance at Llandidno, in Denbighshire. It has rather the appearance of a vegetable than mineral production, and is most commonly found of a beautiful velvety appearance. The upper surface is extremely tender, and bruises on the slightest touch, assuming a whitish appearance. The sides become more or less white on exposure to the air, and when fresh broken, are of a satiny green, formed of fine thready radii. often closely compacted in stratified order, one coat over another, rightly compared by Mr. Rashleigh to the coating of an onion. It is found from a light to a dark green; the surface is sometimes tinged with, and passing into a red, or crimson. Its form is generally in protuberating knobs or mammillæ. Malachites, though well known in many parts of England, have been generally esteemed foreign productions: Dr. Babington, however, mentions the harder sort, resembling the foreign, being found at Helstone, and the Land’s End in Cornwall, in the South of Wales and Yorkshire. We have it from Wheal Unity, and many parts of Cornwall. The softer sort is not unfrequent among copper ores, with the other which we have from North Wales, as before mentioned; and our dear friend. Dr. Ridout, was so good as to give us a specimen which he gathered himself at Dodington mine, in Somersetshire. They are said to contain from 66 to 75 per cent. coper. 19.4 carbonic acid, and 5.6 water, and sometimes a little arsenic. Hardness, 5–7. Kirw. Spec. Grav. 3.5 to 3.994.

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