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Zincite, found massive in New Jersey, U.S.A., is an attractive deep red colored mineral, a few pieces of which have been cut into gem stones. It is a red oxide of zinc, generally translucent, but containing impurities such as traces of manganese, which give it its color. It has a fairly high specific gravity, although it is relatively soft. It dissolves in acids without effervescence.

Taaffeite. Named after Count Taaffe of Dublin, who first recognized this stone in 1945 as having some different properties from other known minerals, only two cut specimens are so far in existence. But others may exist, especially in mixed parcels from Ceylon, and which may unknowingly be thought to be spinels, chrysoberyls, or sapphires. As will be seen by its physical properties, resemblance to spinel is very close. Refractive indices are 1.72-1.73, specific gravity is 3.60 to 3.61, and the hardness is 8.

The two cut stones jewelry in question are pale lilac in color; they belong to the hexagonal system of crystallography, being composed of magnesium, beryllium, aluminum, and a trace of iron.

Willemite, or wilhelmite, is an anhydrous silicate of zinc, but gem material is very scarce. Clear, pale yellow stones have been found, and these have the peculiar property of phosphorescing after exposure to magnesium light and fluorescing in ultra-violet rays. Creenish-yellow and brownish stones are also found, transparent to opaque, and the crystals take the form of hexagonal prisms. A silicate of zinc, it is an important ore of this mineral. New Jersey, U.S.A. and Belgium are the chief sources of supply. It was named after William I, king of the Netherlands.

Wardite is a hydrous aluminum phosphate, light green to bluish-green in color, but it is not cut as a gem stone. It is found with variscite in Utah, U.S.A.

Scapolite is a term which really applies to a group of minerals which have slightly varying composition, the constituents being silica, alumina, and lime. Material suitable for cutting into gem stones has not long been discovered, and it usually occurs in crystalline and limestone schists, the crystals belonging to the tetragonal system.

Scapolite is also found in massive, granular, and columnar forms. Pink stones come from the ruby mines of Mogok, Burma, and yellow material has been found, together with beryl, in Madagascar and Brazil. Pale shades of blue and green are also mined, the material varying from being transparent to opaque. Scandinavia, Canada  (Ontario and Quebec), and the U.S.A. are additional localities to those already mentioned where scapolite is found.

The name is derived from two Greek words, meaning “rod” or “club,” and “stone,” which refers to the long prismatic crystals in which the stone usually occurs.

Saussurite, a decomposed lime-feldspar and allied to labradorite, occurs in compact or finely granulated masses. Greenish or white In color, it is seldom used. It is found in Canada, Switzerland, and in other localities.

Sinhalite. This mineral has only comparatively recently been recognized since it has previously been confused with other very similar stones. Some examples have now been identified in parcels of assorted stones originating in Ceylon, but no doubt it occurs in other localities. It closely resembles chrysoberyl, olivine, and zircon, being a magnesium aluminum borate, with a trace of iron.

The color is pale, brownish yellow or greenish brown, and specimens are usually free of flaws. Dichroism is distinct, and the specific gravity varies slightly between 3.47 to 3.49, the darker brown stones being the heaviest. Refractive indices are 1.66-1.70 approximately. Bands are to be seen in the blue part of the absorption spectrum, with general absorption of the violet. Very few cut specimens are as yet known.

Staurolite is a hydrated iron aluminum silicate, reddish brown in color, and found in crystals (often twinned) of the rhombic system. The material is generally opaque and unsuitable for use in jewelry. Switzerland and North America produce rough material, which is found in metamorphic rocks.

The name is derived from the Greek stauros, meaning “a cross,” as the twinned crystals often have a natural cruciform arrangement.

Rutile is a binoxide of titanium, and thus is identical in composition to anatase. When cut, the transparent red stones are attractive since they possess a high refractive index and almost a metallic luster. Dark brown stones are the more usual; when black, they are known as nigrine. All colors show distinct dichroism.

Material is widely distributed, crystals being found in the U.S.A., France, Brazil, and Norway. In the past, this ore was used in porcelain painting to produce black, or if sparingly used, a deep violet-blue color. It has also been used in the coloring of artificial teeth, as well as imparting a violet color to glass. For these reasons, it has been manufactured synthetically in the U.S.A., and some synthetic material cut as jewel stones has even appeared on the market. Care should be taken to distinguish these from sphene and diamond since they show a considerable amount of fire.

Rosinca. This is the name given to the rose-veined type of rhodochrosite. It has lately been used as an ornamental stone, boxes and larger objects being either veneered or made with slabs of this material.
The present supplies apparently come from the Thirteenth Century silver mines of the Incas in South America. The stone is fairly soft, and it is usually found in a massive state, although rhombohedral shaped crystals occur also. The stone somewhat resembles rhodonite, but the latter is harder. Moreover, hydrochloric acid will affect rhodochrosite, but no effervescence would be seen with rhodonite. On exposure to air, rosinca tends to lose its color.

Apart from Argentina, this stone is found in England (Shropshire and Warwickshire), Hungary, Germany (Harz Mountains and Saxony), Newfoundland, and Connecticut. Rhodochrosite is of Greek derivation, rhodon meaning “a rose,” and chrosis “color.”