Here is a spectacular and informative guide to the amazing world beneath our feet. Stunning color photographs of rocks, fossils, minerals, precious metals, crystals, jewels and gemstones give the reader a unique eyewitness insight into the evolution and composition of the Earth. See rocks that have come from outer space, stalactites as old as dinosaurs, the strange and beautiful shapes of natural crystals and priceless nuggets of gold, silver and platinum. Learn what the Earth is made of - and how its rocks were formed, how early humans made the first flint tools and how diamonds and precious stones are cut, polished, and made into jewelry. Discover how prehistoric animals are preserved today as fossils, how volcanoes work, how rocks are formed from molten lava, how minerals and metals are mined and how pebbles on the seashore are worn down into sand, and much, much more!
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.
|Head Width||6 3/8 inches|
|Overall Length||11 inches|
|Head Weight||14 ounces|
|Total Weight||1 pound 5 ounces|
The BelOMO 10x21mm(.85") triplet loupe magnifier has a viewing area of 0.65 inch (17mm), much larger than the Bausch & Lomb Hastings Triplet Magnifier. The 3 elements making up this achromatic triplet provide a bright and clear view. The 10x power magnification provides the best magnification to depth of field ratio and is the most popular power for a hand held magnifier. The housing and cover are machined metal and coated with a matte black finish and assembled using flathead screws. Belorussian Optical and Mechanical Association (BelOMA), makers of sights for guided weaponry, camera lenses, and other optical components manufacturers these loupes.
We highly recommend this loupe. This is the lens we use all the time.
Each BelOMO loupe we ship is custom treated to prevent the screws from coming loose with usage.
A Correlated History of the Universe (WMPTP000) is a full-color educational foldout chart. On one side is "A Correlated History of the Earth" and the other side has "A Correlated History of Matter". This is not only a great study guide for the student but it can also provide hours of interesting entertainment for anyone interested in the steps and stages of the universe! A reference for: Astronomy, Geology, Paleontology, Physics & Chemistry. v III, 2009
Save $5.00! We still have a few copies of "A Correlated History of Matter", v II, 2002. While it doesn't have the latest updates and additions its content is close to the same and it is still a useful reference guide, fun to peruse, and makes a nice gift.
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