Which type of sand do not absorb water?
Quartz and Halite Compare: Quartz and halite are both minerals and have a white streak. The different possible impurities result in similar mineral colors, such as pink or white. They are also binary compounds. Contrast: Quartz (SiO2) is a silicate and is covalently bonded. Halite (NaCl) is a halide and ionoicly bonded. Quart has a hardness of 7, and halite 2. Pure quartz is clear, while pure halite is white. Quartz is much more abundant than halite. Graphite and Diamond Compare: Graphite and diamond are polymorphs of carbon. Both (in their pure form)are composed entirely of carbon, but the atoms of carbon are bonded differently. Contrast: The difference is because of the crystal structure an bonding between carbon atoms. In graphite, the atoms form stong bonds to form a hexagonal sheet or plate. Between these, however, bonding is very weak, and so graphite is soft and easily broken apart. Diamond, though, has carbon atoms bonded strongly in all directiions, so it is very strong and hard. Graphite has a hardness of 2, while diamond has the highest at 10. Graphite is dark grey with a dull luster, while pure diamond is clear and sparkles.
This sounds as though there are specific specimens you were to look at. So use any answers posted here with caution. Halite belongs to the cubic crystal classification, and no matter how you break it, the crystals will always look cubic, or at least rectangular with parallel sides that are 90o from each of the other two sets of sides