Gems Notes and Extracts Augusto Castellani, Mrs. John Brogden 1871

180 GEMS.The pyroxenum Jiederibergite,from the name of thechemist Hedenburg, is dark -green and almost black ;itonly contains protoxide of iron, to which there issometimes united a quantity of magnesia.Ingeneral, pyroxenum of every qualityis but littleused, although well adapted for jewellery, in makingornaments for mourning.LXXX.PISOLITE.THIS stone, which iscommonly called pisinella stone,differs from the oolite, to which it is related, in thelarger dimensions of the aggregated particles, which, init, are composed of concentric leaves.Like the oolite, it iscomposed of small spheresunited by a calcareous cement, and it is found ofdifferent colours reddish, brown, yellowish, andwhite.It looks well when cut and polished. It is found inthe alluvial deposits of the warm waters, rising atCarlsbad, in Bohemia, and at the baths of San Filippo,in Tuscany. Its name is derived from TTIO-OS, pease,, stone, on account of its most common colour.