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Show Parle Service Report Stable Quartz Plays Important Role In Story of South eastern Utah Si02, silicon dioxide, chert, sandstone, granite, radio crystals, crys-tals, flint, jasper, pegmatites, these are all rocks and minerals min-erals and objects that have one thing in common. They are composed' partially or entirely en-tirely of the common mineral quartz. Probably no other mineral plays such an unobtrusive unob-trusive but important role jin our lives. Quartz, and associated as-sociated quartz minerals, comprise the largest percentage percen-tage constituents of Hie rocks that surround us. Such a numerical dominance domin-ance implies several things. First, the mineral must be rather stable, difficult to breakdown in the weathering process. Second, a great deal of quartz must be available from some source basic to the early earth history. Third, new quartz being brought io the earth's surface must replenish re-plenish title iniftial surface supply. And last, the mineral, although stable, appears in several forms or modes of occurences. Let's look at et' these several points a.id see if they apply to the country we live in. Quanfz is a stable mineral. All of the. minerals that make-up make-up the : rocks' of the earth have been clasified according to .their hardness. An arbitrary arbi-trary scale ranging from a hardfiess of 1 (very soft: chalk)' to a hardness of lu . i(very 'hard: diamond) will include all 'the: (naturally oc-Icuring oc-Icuring minerals of the world, Quartz has a hardness of ji. It . caii scratch a groove in window glass,' but cam not foe' scratched by the blade of an ordinary pocketknife. The silicon1 and oxygen atoms of the quartz crystal are tightly bound : by molecular attraction.' attrac-tion.' Many gem hunters find heautiful, six-sided quartz crystals, "growing", in the rocks. The Uninformed gem hunter .may try' to break a large 'crystal' with his hammer.- He is hoping to fracture the njineral along cleavage planes and .produce one or more smaller, six-sided crystal crys-tal specimens. He is in for a disappointing lesson in min-erology. min-erology. Quartz will shatter into sharp, conical surfaces When' hit with a hammer, and not into new, smaller crys- . tal faces; How hard is quartz? IWe said it had a hardness of 8,- Don'it go around the ' house" scratching . your win-odws win-odws to. test this:. Wait until you are caught on the highway high-way in a desert sandstorm. Soon your clear glass will be frosted with billions of little pits. This is the result of quartz grains, propelled by the strong wind, bombarding bombard-ing the glass surface. Where dees all the quartz come from? Our continents are literally islands of acidic igneous rock floating on a sea of denser, basic igneous rocks. Acidic igneous rocks (granite is an example) are rich in quartz. In the beginning begin-ning of the earth', after our atmosphere was formed and the earth's crust cooled, (these island continents were all that was exposed above the first oceans. Weath".r::i3 products of these acidic ij-mleous ij-mleous rocks soon began to blanket the continents in the form of sandstone, silt-stoines silt-stoines and other sedimentary rocks. Thl9 process continued contin-ued through the millenniums. In turn, the first sandstones, rich in quartz, weathered to produce younger sandstones, richer in quartz. The less stable minerals were gradually grad-ually being removed or re- duced to fine clays. That little, lit-tle, annoying sand grain that l ed -re d in your eye on the last' tr p to the Arches, it could have originated from a huge quartz ton', days when the & ped against thej . skeletal North . continent. |