Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Identifying Minerals Minerals can be identified by their properties. One or more properties may be needed to properly identify most minerals. MINERAL TESTS 1) Hardness Mohs Scale of Hardness. 1) Talc 2) Gypsum 3) Calcite 4) Fluorite 5) Apatite 6) Orthoclase 7) Quartz 8) Topaz 9) Corundum 10) Diamond # 1 softest # 10 Hardest #3 can scratch 1 and 2 but not #4 Hardness is determined by scratching not toughness. Diamond is the HARDEST substance and its prime use is as an abrasive. 2) Color--- Many minerals can be identified by color. This is not always reliable because there are so many variations in mineral types. SULFER is always yellow. 3) Streak--- The color of a finely powered mineral is known as streak. Although the color of a mineral may vary, its steak does not and is therefore a good indicator of mineral type. Streak is tested for by rubbing a specimen on a streak plate (porcelin). 4) Cleavage--- A mineral has cleavage if it breaks along definite planes. Cleavage depends on crystal structure and takes place parallel to atomic planes. EX---- Halite , Flourite. 4) Fracture--- The way a mineral breaks when it does not Follow cleavage planes, Examples, are glassy, (conchoidal) hackly, splintery, and any other way that is not a smooth surface 5) Luster----- the way a mineral looks in reflected light. Can be described a glassy, oily, dull, earthy, metallic, pearly, adamantine, sparkly. 6) Specific Gravity (Heft) --- a comparison of the density of a mineral with the weight of water. Ex--- density of water is 1 gram / cm3 Density of limestone is 2.67gm/cm3 Density of gold 19.3 gm/cm3 7) Magnetism---- Many minerals contain iron or nickel and may be attracted by a magnet. Some are magnetized and will attract iron EX—Magnetite. 8)Acid Test-- If a mineral has carbon and O2 in its composition it will “ fizz” when weak hydrochloric acid is dropped on the sample. CALCITE LIMESTONE CHALK all contain CaCO3 MARBLE and will fizz. Mineral tests are used with a guide to help identify mineral by a process of elimination. If a mineral does not fizz during an acid test, then it could not be calcite. If a specimen could be scratched by a fingernail, it could not be quartz. All tests need not be used to identify all minerals, some are obvious, like pyrites metallic luster, or magnetites magnetism, or the hardness of diamond.