Botryoidal Datholite, or, Botryolite

Throughout the mineral kingdom each species is found to occur under several various general forms, with few exceptions; in many the different forms may be traced from one to the oilier; hut in some they are very dissimilar and without any intermediate link; of the Latter class are the two leading varieties Datholite, which have been looked upon as distinct species by many Mineralogists, although they are not more dissimilar than many varieties of Carbonate of Lime, &c. are to each other: but external form cannot be admitted as a specific distinction, since it is so variable in substances of the same composition. The mammillated, or botryoidal Datholite, is composed of concentric coats of diverging fibres, closely compacted together, and forming a dull smooth surface. It is found in the Kjenlie Mine, near Arendal. in Norway, from whence the specimen figured was brought.

The matrix of the specimen figured is chiefly Carbonate of Lime, with Quartz, Hornblende, and green Phosphate of Lime.

From the British Museum.