The determination of the hardness of a mineral can be an important step toward its identification. Hardness is the resistance which the smooth surface of a mineral offers to being scratched. A diamond is the hardest of all substances, and can only be scratched by another diamond. Over a century ago, Friedrich Mohs, through a series of experiments, made up a scale of hardness which is now referred to as "Moh's Scale." It does not imply an exact harndess, but is set up so that any mineral can scratch all those beneath it in the scale, or can be scratched by those above it in the scale.
This set contains 9 different minerals, each corresponding to a different position on the scale. Each mineral is given a number, 1 being the softest (talc), and 9 the hardest (corundum). Diamond is, unfortunately, not included, but this kit will give you a good sense of the hardness scale up to that point! This kit can be used as an introductory mineral sample kit for kids to spark an interest in geology, or as a fun project; the kit includes white and glass streak plates, a penny, and a nail so you can test the hardness and color streaks for all your minerals. The minerals featured in this kit, in order from softest to hardest, are talc, gypsum, calcite, fluorite, apatite, feldspar, quartz, beryl/topaz, and corundum.
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