Native Bismuth

This is a rare substance as British. It came from Cornwall and was among the specimens t had the good fortune to procure of the late truly ingenious Mr. Day. It appears in the centre of Amorphous Brown Quartz. It has some admixture of gray or dark Sulphuret and other substances; perhaps Cobalt, with Oxide of Iron, &c. At Johann-Georgenstadt and Sneeburg in Germany, it is sometimes found crystallized in four-sided tables, in somewhat cubical or truncated tetraëdrons. Its primitive form is an Octaëdron. The colour of the present varies from whitish to tarnished yellow, reddish or purple; metallic fracture more or less perfectly foliated, folia parallel to the planes of a regular octaëdron. The peculiarly beautiful crystallization of this substance obtained by melting it in a proper degree of heat, and then suffering it to cool, attracts attention:—see the lower figure. The square or right-angled volute might afford an excellent natural lesson or model for a square column, pilaster, or frieze, in the hands of a good architect. I conceive the original and best forms of the ancients were derived more from natural subjects than is generally thought.