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.
Aluminum Oxide. Aluminum oxide is a common, naturally occurring compound thatâs employed in various industries, most particularly in the production of aluminum. The compound is used in production of industrial ceramics. Its most common crystalline form, corundum, has several gem-quality variants, as well.ses in Ceramics. Aluminum oxide, also called alumina, is used in engineering ceramics. Itâs hard and wear-resistant, resists attacks by both acid and alkali substances, has high strength and stiffness, and has good thermal conductivity, which makes it valuable in manufacturing a variety of different ceramic products.