Let us not complain if we cannot possess works of art wrought by human brains and hands, when we often fail even to look at, much less appreciate, the daily art of Nature which is our birthright, and which perhaps we regard but lightly, because it is free to everyone with seeing eyes and beauty-loving soul. Let us rather cast off the scales that blind our eyes and hide from us the visible expression of a Creator’s love, the beauty of Nature.
And our lives shall be enriched an hundred fold.
Anne Wakely Jackson.
QUARTZ.
This is the most abundant, most durable and most indestructible of common minerals. There is scarcely a sand beach, field or mountain side upon which this mineral cannot be found in some form or other. Its abundance is due not so much to its excess in quantity in the underlying rocks as to the fact that, being harder and less easily decomposed than other minerals, it remains after they are worn away.
Though so common, it appears in so great a variety of colors and different kinds of structure that a large collection of minerals looking very much unlike might all be made up of Quartz. If they were all of Quartz they would have the following characteristics: Hardness, 7 (cannot be scratched with a knife blade); specific gravity, two and a half times as heavy as water; no cleavage; fracture conchoidal (shell-like); infusible before the blowpipe; insoluble in common acids. The numerous varieties of Quartz can be grouped into two classes, the pheno-crystalline (plainly crystalline) and the crypto-crystalline (obscurely crystalline). This article deals with the plainly crystalline varieties. These include, among other varieties, rock crystal, amethyst, rose quartz, smoky quartz, and sagenitic quartz. These varieties all occur in well formed crystals, and all have a vitreous luster, i. e., luster like that of glass. The differences between them are almost exclusively differences of color.
Rock Crystal—This is quartz in its purest form. Typical rock crystal is perfectly transparent and colorless, but the mineral is often more or less clouded and opaque. By the ancients it was supposed to be petrified ice, and hence the Greeks applied to it their word for ice, from which we get our word crystal. The belief in its ice origin survived to a comparatively late period, for in 1676 Robert Boyle opposed the idea, stating that the quartz could not be ice, first because it was two and a half times as heavy as water, and second because it was found in tropical countries. The belief of the ancients probably came largely from the fact that the quartz they knew was obtained from the peaks of the Alps. They reasoned that it was ice that was frozen so hard that it would never melt. Fortunately our present knowledge of chemistry prevents us from any longer confounding the two substances, for we know Quartz is oxide of silicon while water is oxide of hydrogen.
Quartz in the form of rock crystal occurs in all parts of the globe, and for the most part in well-formed crystals. These crystals are usually six-sided, and usually have the form of a prism capped by a pyramid. Hot Springs, Arkansas, and Little Falls, New York, are the best known localities in our own country for this form of crystallized quartz. The Little Falls crystals are exceptionally brilliant and well formed. From this locality and others the material, cut or uncut, is often known as diamonds, and sold as such. Such stones can, of course, be easily distinguished from true diamond, for while they will scratch glass, their hardness is much below that of the king of gems and they utterly lack the internal fire of the latter.
Rock crystal occurring in large, clear masses is often cut into ornamental and useful objects such as seals and paperweights, and especially into balls. The latter industry flourishes especially in Japan, and perfectly clear quartz balls six inches in diameter are made there.
Rock crystal is also used extensively to cut into eyeglasses and spectacles in place of glass, some considering it less detrimental to the eyes than glass. It is also occasionally used for mirrors, it being superior to glass for this purpose, in that it does not detract from the rosiness of the complexion.