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Articles about rockhounding. Collecting rocks, displaying rocks, exchanging rocks and buying rocks. We specialize in Southern African minerals and rocks but we endeavor to carry interesting articles for people everywhere. Do send us an e-mail with anything interesting that you have written about rocks in your area and we might publish it here. Every month we will post a new article to this website.

 How to identify a mineral

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	How to identify a mineral
1	Determine what the streak is
	A simple method for the rough identification of a mineral is to look at it's streak, also called powder color. A mineral may have  different colors but it will always display the same streak. There is six basic streak colors. White and colorless, green, grey and black, red and orange, gold and brown and blue. Now you are asking but how do I test the streak? The inherent color of the mineral can be determined by drawing the mineral over an unglazed porcelain tile, also called the streak plate. The line of color left gives you the streak color. When the minerals hardness is higher than the tile you first need to pulverize a bit of the mineral and then look at the color against a white background. As we would say in Afrikaans, "Eina" That is translated to: "You are hurting me". I am not advocating ruining your mineral.
2	What is the Moh's hardness?
	Freidrich Mohs (1773-1839) has determined that every mineral has a specific hardness and he developed the Moh's hardness scale. This is a scale of ten common minerals of increasing hardness. Scratch hardness 1 represents the softest mineral, 10 the hardest.
	Moh's Hardness Mineral Simple testing devices Absolute hardness 1 Talc Fingernail; rubbing 0.03 2 Gypsum Fingernail; scratch 1.25 3 Calcite Copper coin; scratch 4.5 4 Fluorite Knife; scratch easily 5 5 Apatite Knife; can still scratch 6.5 6 Orthoclase Steel file; scratch 37 7 Quartz Will scratch window glass 120 8 Topaz 175 9 Corundum 1000 10 Diamond 140 000
3	What is the specific gravity?
	This characteristic - also called "relative density" - is often the one that will make a positive identification of a mineral possible. Specific gravity is the weight of of a specific material compared with the weight of the same volume of water. The specific gravity of minerals varies between 1 and 20. Values under two are considered light. Those from two to 4 are normal and those above 4 are heavy (Lead 7.5) See our article on Specific gravity.
4	Additional determinations
	Most of the time the previous three determinations will be enough to identify a mineral. You might have to look at another property of the mineral such as, color, luster or transparency. Sometimes the crystal habit or shape will give it away.