Some horses, especially older horses that are very relaxed, let their lower lip droop markedly. This is usually a normal finding. When these horses become more stimulated, the appearance changes. The key to this is that the appearance is symmetrical on left and right sides.
Because of corundum's hardness (pure corundum is defined to have 9.0 Mohs), it can scratch almost every other mineral. It is commonly used as an abrasive on everything from sandpaper to large machines used in machining metals, plastics, and wood.orundum from Brazil, size about 2 cm Ã 3 cm (0.8 in Ã 1 in). Corundum occurs as a mineral in mica schist, gneiss, and some marbles in metamorphic terranes. It also occurs in low silica igneous syenite and nepheline syenite intrusives.
Pure corundum is colorless, transparent, durable, and scratch resistant. Large crystals of clear synthetic corundum are grown, sawn into thin sheets, and then used as the windows of grocery store scanners, watch crystals, aircraft windows, and protective covers for electronic devices.ost people are familiar with corundum; however, very few people know it by its mineral name-instead they know it by the names ruby and sapphire.. A gemstone-quality specimen of corundum with a deep red color is known as a ruby..