Hematite (from Greek: αιμία, Haima, blood) is a mineral which is mainly composed of ferric oxide crystals (iron (III) oxide, Fe2O3), one of the iron oxides. It comes in addition to other varieties like the red blood stone and gray-black to black gloss iron and iron oxide. The mineral has a hardness between 5 and 6. The so-called stripe, stripe or color, the color issuing the mineral to rub on an unglazed porcelain dish, usually a characteristic blood-red - the mineral it takes its name. It may contain trace amounts of magnesium, manganese and titanium mineral. Hematite comes both before and going as mineral in sedimentary layers. It is often the cause of reddening of many rocks. Along with hematite often other iron ores such as magnetite, limonite and iron ore. If magnetite is converted to hematite is called martite. The mineral occurs worldwide, in Europe, in Germany, among others in the area of the Lahn which is the world's largest concentration of iron ores in the Eifel Mountains, the Harz Mountains and the Thuringian Forest. Furthermore, in England in Cumberland and North Lancashire, in Belgium in Vezin and Namur, on the Italian island of Elba and in Spain. In Africa, Algeria is a significant producer and in the United States of America it is found at the Upper Lake and at the Missouri. More than half of world production now comes from China, Brazil and Australia. In addition, the mineral is also in high concentration on the surface of the planet Mars. This creates the typical orange-red color of the "Red Planet". The mining of hematite is one of the earliest mining of humanity: the powdered mineral was found in about 80,000 years old graves. Both on the Greek island of Thassos and in the places Rydno in Lovas in Poland and Hungary, have grooves known from the Palaeolithic. Also in Germany, traces of prehistoric mining of similar size found in Bad Sulzburg and in Münster from the time around 5000 BC that the Linear Pottery Culture at the Topline are due. The Etruscans had already abundant prevent iron shine known on the island of Elba.
Tiger eye is a quartz variety. The color of the stone is yellowish brown to brown, streaked and opaque. Repositories include Africa, India, Mexico, California and Australia. Tiger Eye is caused by silicification of black blue crocidolite asbestos fibers that are called. This produces solid inclusion of hair-like crystals in the quartz. By the oxidation of the original crocidolite fibers rise to the gold shiny limonite fibers of the stone. Tiger Eye is so called because the stone has a light reflection reminiscent of the eye of a tiger. This slit-shaped light hot chatoyeren or kattenoogeffect. When the stone cabochon (BOL) is cut, the beautiful kattenoogeffect is most visible. The color of the stone gives it its name: the red species called Catseye, the Hawkeye blue and yellow Tigereye (golden yellow, golden brown)