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.
It is second only to the hardest substance on earth- the Diamond. Corundum is found usually where silica sands are not. While many gemstones come from silica, including Quartzâs, Corundum is usually mined away from these types of rocks. Rubies are much less common and naturally donât usually occur often. Rubies are usually the result of chromium and titanium inclusions in Corundum.