Jasper Jasper Jasper, an aggregate of microgranular quartz and/or chalcedony and other mineral phases, is an opaque, impure variety of silica, usually red, yellow, brown or green in color; and rarely blue. The common red color is due to iron(III) inclusions. The mineral aggregate breaks with a smooth surface and is used for ornamentation or as a gemstone. It can be highly polished and is used for items such as vases, seals, and snuff boxes. The specific gravity of jasper is typically 2.5 to 2.9. A green variety with red spots, known as heliotrope (bloodstone), is one of the traditional birthstones
Non-metallic inclusions has a big influence on the metal properties. Present-day methods of steel and alloy production are unable to attain completely pure metal without any non-metallic inclusions. Inclusions are present in any steel to a greater or lesser extent according to the mixture and conditions of production. Usually the amount of non-metallic inclusions in steel is not higher than 0.1%. However, the number of inclusions in metal is very high because of their extremely small size. Non-metallic inclusions in steel are foreign substances. They disrupt the homogeneity of structure, so their influence on the mechanical and other properties can be considerable.