Silicon Carbide is often referred to as “salamander quartz” and can be processed in different ways depending on application. Variations of porosity, density, surface hardness, chemical purity, temperature range and thermal shock resistance can be altered with different production methods. Small and large dimensions as well as different geometries can be produced. To cover all options in detail here might be too extensive. Nevertheless silicon carbide seems to be the perfect material for most precious metal applications with a temperature range of up to 3000 °C. Even beyond this point the material does not melt, but sublimes instead. Over 800 °C the crucible forms a thin protective layer of silicon dioxide (SiO²) against further oxidation. This effect lengthens the product life time immensely in applications under oxygenic atmosphere. The layer can be seen as a glassy shimmer on the crucibles. From 1600 °C upwards this protective layer would dissolve in case of lack of oxygen by forming the gaseous silicon monoxide (SiO). The crucible would burn away from cycle to cycle in this case. This can be prevented by using the crucibles in shielding gas atmosphere or vacuum furnaces in order to lengthen the life time. Under shielding gas or vacuum the crucibles can even be used up to 3000 °C and dissolves beyond this temperature instead of melting. In its purest form, silicon carbide is colorless, but in all technical applications it is mixed with different amounts of alumina (Al²O³), making it look greenish-black. The blacker the material the more alumina is in the material. With lower amounts of Alumina the green color prevails. In precious metal melting the black silicon carbide is mostly used. Green versions are much more difficult to produce and therefore more expensive than necessary for this application. Silicon carbide is highly resistant to acids and thermal shock. The latter enables faster heating and cooling. The material shows a high thermal conductivity and can be used in induction furnaces. It can be used for melting all precious metals, alloys and mixed metals (recycling). Only limitation would be platinum, palladium and rhodium intended for use in investment bullion or medical market as there might be small impurities in the finished product, not fully qualifying them for these purity grades.