Crystallized Native Silver

This specimen of Crystallized Native Silver, accompanied by Flowers of Cobalt, was sent me from Alvaminein Stirlingshire by my kind friend formerly mentioned in this work by the name of G. Laing, Esq. It is a very useful specimen, as exhibiting a very elegant arrangement of the primitive nuclei, if I may so call these minute octaëdrons, to see which the help of a magnifying glass is required; and we may indulge a conjecture that the Silver settled from its solvent, whatever that was, at the time the mass was soft, which, when hard, retained it in this state for our instruction.—Thus we see the nuclei arranging themselves from loose or distant order, as if preparing to form the close and compact order that is sometimes seen. There being small octaëdrons placed at right angles, and then others arranging in the intermediate spaces, is admirable. We are here informed, as it were, that an accumulation of octaëdrons may be so minute as nearly to fill the interstices, seeming to exclude the necessity of the tetraëdrons, which, I believe, have not been found in Silver.

Thus we have a British specimen of what is reckoned the primitive form of Silver. The matrix of the upper specimen is chiefly Quartzose, with some grey Silver having the Native Silver in spots or blotches, and the Cobalt in a white and husky powder. The lower specimen consists chiefly of Limestone, with minute crystallized Silver among the grey Silver which is represented larger. The rose-coloured and whiter parts are Flowers of Cobalt, or pulverulent Arseniate of Cobalt.