Joseph Ricci, age 11, of St. Catharines, nt., for his question:
What is quartz?
Suppose there were no diamonds hidden in the earth. No sapphires, no topaz and none of the other precious gem stones. The jeweler’s shops would still be filled with glittering stones. And most of these so‑called semi‑precious stones would be composed basically of quarts.
The quartz family includes diamond clear quartz crystal, rose crystal and smoky crystal. Violet toned amethyst is a form of quartz. Translucent chalcedony, silky cans eye, clear red carnelian, rich red jasper, black onyx and even precious opal are all forms of quartz. If the diamond and its sister gem stones disappeared, there would be no shortage of colorful jewels.
Nature was thrifty with her precious stones and hid only a few of them in the ground. They are rare and this is one reason why they are so valuable. Beauty of color and of crystal also add value. Too, most of the precious stones are very durable. The diamond is the hardest of all natural minerals. It can scratch any other stone and no natural stone can scratch it back.
The scale of hardness is very important in judging the nature of a mineral. The diamond is in class 10, all by itself. Sapphire is one of tree minerals in class 9 and topaz is in class 8. Quartz is in class 7 of the hardness scale, only a little softer than these valuable aristocrats of the mineral world. And unlike them, quartz is plentiful. In fact, about 12 percent of all the rocks of the earth’s crust are some form of quartz.
As a mineral, quartz rates as a silicate. Its basic ingredient is the element silicon.. Its chemical formula is one part silicon and two parts oxygen. Glowing cats eye has threads of asbestos imprisoned in the quartz stone. Spangled aventurine has tiny scales of mica embedded in the quartz. Jasper is quartz containing hematite or limonite. Agate is a banded stone in which quartz layers were built at first with one impurity, then with another.
Rock crystal is the pure form of crystal quartz. It forms a six‑sided glassy rod ending in six‑sided pyramids. When traces of hydrocarbon organic matter are trapped in the crystal we got smoky quartz. The amethyst gets its violet tones from traces of manganese and dose quartz gets its rosy tints from traces of titanium.
These are some of the varieties of semi‑precious quartz. But most of the earth’s quartz is in bulk form. The milky white pebbles on the beach are made of quartz. The sand on the beach is composed mostly of quartz. There is quartz in granite and sandstone may be made almost entirely of quartz grains. In bulk it is anywhere frown milky white to dark brown, depending upon its impurities. And one form of quartz is shiny, jet black. This is flint, the smallish hard pebbles our remote ancestors used to make arrow heads and to kindle mints first fires.