WebMalachite is a copper carbonate hydroxide mineral, with the formula Cu 2 CO 3 (OH) 2.This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fractures and deep, underground spaces, where the water table and hydrothermal fluids provide the means for chemical precipitation.

WebLeaders of states in the U.S. which have significant mineral deposits often create a state mineral, rock, stone or gemstone to promote interest in their natural resources, history, tourism, etc. Not every state has an official state mineral, rock, stone and/or gemstone, however. State federal district or territory Mineral Rock or stone Gemstone Alabama

WebThe name moonstone derives from the stone's characteristic visual effect, called adularescence (or schiller), which produces a milky, bluish interior light. This effect is caused by light diffraction through alternating layers of orthoclast and albite within the stone. The diffracted light varies from white to blue, depending on the thinness of the albite layers.

WebCitrine may refer to: . Citrine (colour), a shade of yellow Citrine quartz, a yellow variety of quartz; Citrine (protein), a type of yellow fluorescent protein Citrine, a 2016 album by Hayley Kiyoko; Citrine (programming language), a programming language for Unix-like operating systems Citrine, a commonly-used informal name for ABC of Chairmanship by …

WebFormal theory. Formally, a string is a finite, ordered sequence of characters such as letters, digits or spaces. The empty string is the special case where the sequence has length zero, so there are no symbols in the string.

WebHydrothermal synthesis includes the various techniques of crystallizing substances from high-temperature aqueous solutions at high vapor pressures; also termed "hydrothermal method".The term "hydrothermal" is of geologic origin.Geochemists and mineralogists have studied hydrothermal phase equilibria since the beginning of the twentieth century. …

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WebIn creating jewellery, gemstones, coins, or other precious items are often used, and they are typically set into precious metals.Platinum alloys range from 900 (90% pure) to 950 (95% pure). The silver used in jewellery is usually sterling silver, or 92.5% fine silver.In costume jewellery, stainless steel findings are sometimes used.. Other commonly used …

WebVolcanic rock (often shortened to volcanics in scientific contexts) is a rock formed from lava erupted from a volcano.In other words, it differs from other igneous rock by being of volcanic origin. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and metamorphic rocks and constitute an important element …

WebAn asterism (from Ancient Greek ἀστήρ (aster) 'star') is a star-shaped concentration of reflected or refracted light from a gemstone.Asterisms can appear when a suitable stone is cut en cabochon i.e. shaped and polished (not faceted).. A gemstone that exhibits this effect is referred to as a star stone or asteria.The best known is star sapphire, but many other …

WebThe Throne of Jahangir (Urdu: Takht-i-Jahangir) was made of black onyx.It was built by Mughal emperor Jahangir (31 August 1569 – 28 October 1627) in 1602 and is located at the Diwan-i-Khas (hall of private audience) at the Red Fort in Agra, Uttar Pradesh, India.. Superstitions. The ancient Romans entered battle carrying amulets of sardonyx engraved …

WebIn gemology, chatoyancy (/ ʃ ə ˈ t ɔɪ. ə n s i / shə-TOY-ən-see), or chatoyance or cat's eye effect, is an optical reflectance effect seen in certain gemstones, woods, and carbon fibre.Coined from the French "œil de chat", meaning "cat's eye", chatoyancy arises either from the fibrous structure of a material, as in tiger's eye quartz, or from fibrous inclusions …

WebOtodus megalodon teeth are the largest of any shark, extinct or living, and are among the most sought after types of shark teeth in the world. This shark lived during the late Oligocene epoch and Neogene period, about 28 to 1.5 million years ago, and ranged to a maximum length of 60 ft. The smallest teeth are only 1.2 cm (0.5 in) in height, while the largest teeth …

WebLava is molten or partially molten rock that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from 800 to 1,200 °C (1,470 to 2,190 °F).The volcanic rock resulting from subsequent cooling is also …