Enjoy and Learn!
This informatice guide covers the five billiion years of history that have given the earth its present form, including:
Illustrated in full color, this guide is valuable for everyone interested in our planet, the ultimate basis of our present society.
A Classic Guide .... for All Ages.
Our review:''We highly recommends this little guide. It provides a consice overview of geology, rocks and minerals. Great illustrations to help you understand the concepts. This is great reference, carry it in the field.''
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.
|Head Width||Overall Length||Head Weight||Total Weight|
|7 inches||16 inches||22 ounces||2 pounds 1.1 ounce|
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