In this book two renowned experts share their lifelong passion for geodes and their extensive knowledge of world-class geode deposits as they present the latest theories on the formation and occurrence of these amazing mineral gifts of nature.
The most comprehensive book ever written on geodes of the Americas - a definitive reference for serious collectors and a delightful mineral exploration for both experts and novices.
The Mineral Hardness Ruler is a stimulating visual aid, educates in one phase of mineralogy, and provides the standard ruler measurement scales needed in classes.
Rockhounds, mineral enthusiasts, students, teachers, geologists, and any one interested in rocks and minerals will find the Mineral Hardness Ruler a handy visual aid for quick information on mineral hardness.
The two-sided, flexible, glossy, vinyl ruler consists of five scales: three measurement scales and two mineral hardness scales. The measurement scales are in standard ruler measurements of tenths of inches, sixteenths of inches, and millimeters. Mohs' relative hardness numbers are integrated into the inch scales, while a separate scale exists for an absolute mineral hardness scale by Rosiwal.
On one side of the ruler are pictures of the ten common minerals, in full color, selected by Mohs for his relative hardness scale. On the reverse side of the ruler are six common items with their relative hardnesses. These items, along with known minerals, can be used as a handy field kit to test the relative hardness of an unknown mineral.
Hardness is one property of a mineral that can be used to distinguish among similar minerals. A given mineral can scratch any other mineral of the same or softer hardness. Over a hundred years ago, the German mineralogist Frederick Mohs devised the relative hardness scale that has found favor with mineralogists for over a century. Others, such as Rosiwal, formed absolute hardness scales using the same minerals as Mohs. For example, diamond, the hardest substance in Nature is not twice as hard as apatite, 10 versus 5, but over twenty thousand times as hard, 140,000 versus 6.5.
Enjoy the map of 1910 issued by the State Mining Bureau featuring the many mineral deposits of Southern California. This map is divided into four easy to read sections.
The details of Inyo County are outstanding as shown on the map of 1883. The interesting text accompanying this map has been included.
The gemstone site locations have been compiled from many sources and detailed on a modern USGS planometric map. Many sites are may be found east of Owens Lake. The desert area of Southeastern California should be a rockhounds delight.
Map identifies locations of: gold and silver, actinolite, agate, amethyst, andesite, apatite, autunite, aragonite, azurite, anglesite, barite, beryl, bornite, bloodstone, calcite, chalcopyrite, chalcedony, chert, chrysocolla, dumortierite, epidote, feldspar, flourite, fossils, garnet, geodes, hematite, ilmenite, kyanite, jade, jadeite, jasper, limonite, magnetite, malachite, obsidian, olivine, onyx, opal, opalite, petrified palm, petrified wood, psilomelane, quartz, realgar, rhodochrosite, rhodonite, rhyolite, siderite, scheelite, schist, serpentine, stibnite, sphalerite, sphalerite, wollastone, wulfenite, travertine, tourmaline, and turquoise.
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