Pinolite "eyes" pendant from Austria.

Name for a graphite-pigmented, light grey to almost black dolomite with inclusions of white magnesite grains looking like pine kernels (hence the name). Sometimes used as a decorative stone. Magnesite is a mineral ivory white, which consists of magnesium, carbon and oxygen. The chemical formula of magnesite MgCO3. Beautiful specimens are difficult to find and are highly sought after by collectors. The magnesite owes its name to its main component, magnesium. Magnesium is an element abundant in nature. The mineral is found in solid, opaque, microcrystalline masses, very similar to porcelain. It has a dominant color, usually grayish or yellowish white. In the case of well-formed crystals magnesite is colorless and transparent, when it is pure. It is greyish yellow or yellowish white, sometimes no more than translucent when it contains impurities. These are elements such as iron, manganese or calcium, in which the mineral is replaced partially with the magnesium. In ultraviolet "light" crystals exhibit a strong green-white or blue-white fluorescence. The magnesite am often confused with Calcite. A reliable identification method is the salt-acid test: if a few drops of dilute acid will effervesce on the mineral is calcite. Iron is an element that is often replaces a portion of the magnesium into magnesia crystal. As a result, the crystal structure of the mineral does not change. This puts in nature many possible compositions ranging from pure magnesia (magnesium carbonate) and siderite (iron carbonate). Once the mineral contains more than 50% iron carbonate, consider it as siderite. There are basically three stages: pure magnesite, yellow magnesite and siderite. Pure magnesia contains colorless, transparent crystals indicate that the mineral does not contain iron. Yellow magnesite has to have a yellow color and gives a relatively high iron content. Siderite contains a proportion of iron which is higher than 50% and become therefore no longer seen as magnesite. The magnesite is created in different environments. It arises from conversion of igneous and metamorphic rocks. Generally forms the solid deposits. The richest deposits of magnesite are located in Spain. Other countries where the magnesite found many will be Brazil, Italy, Austria, Poland and Russia.