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Articles related to hardness

Mohs Scale of Hardness - Identify Rocks & Minerals - Chemistry
The Mohs Scale of Hardness measures how well a substance resists scratching by another material. You can use this scale to test the hardness of rocks, ...
How to Perform the Mohs Hardness Test - Chemistry - About.com
The Mohs test is one way to determine the hardness of a rock or mineral. You can use the Mohs hardness to help identify an unknown specimen.
Mohs Hardness Scale of Minerals - Geology - About.com
You use the Mohs hardness scale by testing your unknown mineral against one of these standard minerals. Whichever one scratches the other is harder, and if ...
Mineral Identification - Step 3: Hardness - Geology - About.com
Hardness, as measured with the 10-point Mohs scale, is very important to know for mineral identification.
Tutorial on How to Test for Hard Water - Home Repair - About.com
Hard water is anything above 1 grain of hardness per gallon. (A grain of hardness is an amount of calcium and magnesium equal in weight to a kernel of wheat).
Test for Hard Water - Water Hardness - Home Repair - About.com
This tutorial describes a home test to determine if you have hard water.
The Mohs Hardness of Coins - Geology - About.com
The Mohs scale of mineral hardness consists of ten different minerals, but some other common objects can also be used: these include the fingernail (hardness ...
What's the Mohs Scale of Mineral Hardness? - Jewelry - About.com
The Mohs Scale is used to rank minerals by their hardness. Knowing where gemstones rank on the scale is an important factor in their care.
Aquarium Water Hardness - Freshwater Aquariums - About.com
What do the water hardness numbers actually mean? Is 25 mg/l soft or hard? This reference chart shows what hardness numbers mean, from soft to hard.
Wood Flooring - Janka Hardness Rating - Home Repair - About.com
The relative hardness of wood species is measured using what is called a Janka Hardness Rating. This test measures the force needed to embed a steel ball ...
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