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
Aluminium alloy inclusions (AlN), iron oxides (FeO), manganese oxides (MnO), fluorides (NaAlF, NaF, CaF, …), aluminium borides (AlB, AlB), borocarbides (AlCB). Bone ash (Ca(PO)) sometimes added to patch cracks in the trough can be found as inclusions in the melt. Several methods exist to measure the inclusion content in liquid aluminium. The most common methods are PoDFA, Prefil, K-Mold and LiMCA. Measuring the inclusions is of great help to understand the impact of furnace preparation, alloying practice, feedstock mix, settling time, and similar parameters on melt cleanliness. The PoDFA method provides information on the composition and concentration of the inclusions in molten aluminum.