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.
This is a great little pocket guide to rocks and minerals. It uses color drawings to illustrate the rocks and minerals which I find is far more handy that pictures of museum quality specimens. Rocks and minerals in the field often don't know what they're supposed to look like so they are more average than those museum exhibits!
The Estwing Supreme 13 oz Light Weight Rock Hammer is best described as an Estwing Supreme 22oz Rock Hammer that has been slimmed down to reduce weight. The rock pick is similar is overall size to the Estwing Supreme 22 oz Rock Hammer. The handle is narrower but the length is almost the same as is the length of the head. It differs in that the hammer head (square) striking end is a slightly smaller size and length. The pick end is the same length but tapered to a sharper point.Great hammer for digging fossils from sandstone. Note that the 13 oz specifies the head weight not the total hammer weight. The 14 oz is actually the lightest pointed tip rock pick that we carry.
|Head Width||6 1/4 inches|
|Overall Length||12 1/2 inches|
|Head Weight||13 ounces|
|Total Weight||1 pound 12 ounces|
This rock tumbler is the real thing! Light duty rock tumbler actually changes rough stones to beautiful high-luster semi-precious gemstones. You can even make jewelry and key chains with the settings included in this set. Set includes rotary tumbling machine , rough semi-precious stones (including amethyst, jasper, agate, and others), grit, polish, jewelry settings, glue, and instruction manual. Ages 10 and Up. U.L. Listed.
Great little tumbler for kids to learn about mechanical "weathering" (polishing) of rocks. Just like in a stream the rocks are rolled over and over in a grinding powder. In a stream or river the grit would be sand and fine dirts and clays. In this kit the grit and polish are provided. And it only takes about 6 weeks to polish the rocks unlike months and years in a stream!Refill kits available.
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