Ch. 7: Quartz Group - Opal, Rock Crystals, Amethysts, Rose Quartz, Agate, etc.

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	UNITED STATES, CANADA AND MEXICO	139

	dian myths, were believed to be the bolts of the arrows used by their god. It has been extensively used by them in making spear and arrow-points. William H. Holmes, of the United States Geological Survey, thus describes the locality in Utah known as Amethyst Mountain, opposite the valley of Soda Butte Creek: " Riding up the trail, a multitude of bleached trunks of the ancient forests are discerned. ... In the steeper middle portion of the mountain face, rows of upright trunks stand out on the ledges like the columns of a ruined temple, on the more gentle slopes, farther down; but where it is still too steep to support vegetation, save a few pines, the petrified trunks fairly cover the surface and were at first taken to be the shattered remains of a recent forest. The exposures of strata in the first 300 or 400 feet at the base are not good, and but few of the silicified trunks appear above the covering of vegetation. At the height of 500 feet the occurrences become very numerous, and the great size and fine preservation of many of the trunks was a matter of much surprise. Prostrate trunks 40 and 50 feet in length are of frequent occurrence, and not a few of these are 5 or 6 feet in diameter. The standing trunks are generally rather short, the degradation of the compact inclosing strata being so slow that the brittle trunks break down almost as fast as they are exposed, and in many cases the roots are exposed and may be seen penetrating the now solid rock with all their original ramifications. One upright trunk of gigantic proportions rises from the inclosing strata to the height of 12 feet. (See Illustration.) By careful measurement it was found to be 10 feet in diameter, and as there is nothing to indicate to what part of the tree the exposed section belonged, the roots may be far below the surface, and we are free to imagine that there is buried there a worthy predecessor of the giant Sequoias of California. Although the trunk was hollow, and partly broken down on one side, the woody structure was perfectly preserved ; the grain was straight and the circles of growth distinctly marked. The bark, which still remains on the firmer parts, was 4 inches thick and retained very perfectly the original deeply-lined outer surface. It was clear, however, that the tree is not a conifer. The strata inclosing the trunk consisted chiefly of fine-grained sandstones,

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