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.
Height 9.5 Width 6.4
This map packet includes five maps printed on both sides. Maps one through four features gold, silver and gem deposits. The fifth map, side one, shows gold occurrances taken from an 1871 map. Side 2 is a page outlining the history of Oregon's mining operations and how to find and mark your own gold deposits. Every map tells the greatest story! Reported and known occurrences of gold and silver, as well as the popular gem deposits are identified in red. Many secrets of prospecting and mining are revealed in this collection! This publication is attractively packaged for display.
Map identifies locations of: gold and silver, agate, apache tears, bloodstone, carnelian, chalcedony, feldspar, fossils, garnet, geodes, jasper, limb casts, nodules, obsidian, opal, petrified wood, quartz, rhondonite, rhyolite, sagenite, serpentine, sunstones, thunder eggs, tourmaline, jade
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