About SemiPrecious Stones: Satin Spar, Staurolite, and Titanite

The mineral world contains many beautiful materials that are without the pale which encloses the clearly defined gem stones; these "outlanders" may be classed as semi-precious stones that are only occasionally used, and while many are truly beautiful and others are interesting, because of rarity or peculiarities, all lack some quality--usually a sufficient degree of hardness--which would admit them into the patrician rank of Precious Stones. Because of their intense scientific interest, technical mineralogists, who have written books about gems, not only include but devote considerable space to minerals that will not meet the eye of one manufacturing jeweller or gem dealer in one hundred, or ever be seen by one gem buyer in thousands. These stones are usually not so rare in nature as they are in stores, and their cutting and mounting is usually the result of an individual order; otherwise they are collected and cut only for collector's specimens. Brief mention will be here given to some of the minerals that occasionally appear and are included in the stocks of the principal stone merchants. In the American market there is a difference in this respect between the market east of the Pacific coast cities and localities near them or close to the Rocky Mountains and the Sierras, because that mountainous region is a great mineral treasure house, yielding many welcome finds of attractive and beautiful semi-precious stones; therefore in San Francisco, Denver, and other Western cities, these local minerals are used in jewelry to a greater extent than they are in the midland cities and those of the Eastern States.

Among the stones most likely to appear from time to time in the shops are:

SATIN SPAR is a form of gypsum, white, with a delicately fibrous structure, which, when polished, exhibits a beautiful silky lustre and pearly opalescence. It appears in the jewelry trade sometimes in necklaces, charms, and pendants. A great trade in these articles is a constant source of revenue at Niagara Falls, tourists being ready purchasers on the assumption that the mineral is native to the region; gypsum is found at Niagara Falls but not of this variety; the raw material thus used is obtained in Wales.

STAUROLITE occasionally appears among the stones handled in the trade. Colour, reddish brown to brownish black; hardness, 7.5. The transparent kinds when cut resemble garnets. Because of their resemblance to a cross, the twinned forms are used to quite an extent as ornaments and charms; there is a tradition that they fell from heaven.