Top Ten Minerals

Top Ten Minerals

SapphireRuby1Emerald3

A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not have a specific chemical composition. Minerals range in composition from pure elements and simple salts to very complex silicates with thousands of known forms. The study of minerals is called mineralogy.

  1. Diamonds
    Public DomainDiamonddiamondsThe Incomparable
    In mineralogy, diamond (from the ancient Greek αδάμας – adámas In mineralogy, diamond (from the ancient Greek αδάμας – adámas “unbreakable”) is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions. Diamond is renowned as a material with superlative physical qualities, most of which originate from the strong covalent bonding between its atoms. In particular, diamond has the highest hardness and thermal conductivity of any bulk material. Those properties determine the major industrial application of diamond in cutting and polishing tools and the scientific applications in diamond knives and diamond anvil cells. Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency, this results in the clear, colorless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) color diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red. Diamond also has relatively high optical dispersion (ability to disperse light of different colors), which results in its characteristic luster. Excellent optical and mechanical properties, combined with efficient marketing, make diamond the most popular gemstone. Most natural diamonds are formed at high temperature and pressure at depths of 140 to 190 km (87 to 120 mi) in the Earth mantle. Carbon-containing minerals provide the carbon source, and the growth occurs over periods from 1 billion to 3.3 billion years (25% to 75% of the age of the Earth). Diamonds are brought close to the Earth surface through deep volcanic eruptions by a magma, which cools into igneous rocks known as kimberlites and lamproites. Diamonds can also be produced synthetically in a high-pressure high-temperature process which approximately simulates the conditions in the Earth mantle. An alternative, and completely different growth technique is chemical vapor deposition (CVD). Several non-diamond materials, which include cubic zirconia and silicon carbide and are often called diamond simulants, resemble diamond in appearance and many properties. Special gemological techniques have been developed to distinguish natural and synthetic diamonds and diamond simulants.
    Links: Top Ten Diamonds, Top Ten Works of Art by Damian Hirst, Top Ten Skulls, Top Ten Human Skulls, Top Ten Skull Artifactshttp://en.wikipedia.org/wiki/Diamond,
  2. Loadstone
    LoadstoneLoadstone1
    A lodestone or loadstone is a naturally magnetized piece of the mineral magnetite. They are naturally occurring magnets that attract pieces of iron. Ancient people first discovered the property of magnetism in lodestone. Pieces of lodestone, suspended so they could turn, were the first magnetic compasses and their importance to early navigation is indicated by the name lodestone, which in Middle English means ‘course stone’ or ‘leading stone.’ Lodestone is one of only two minerals that is found naturally magnetized; the other, pyrrhotite, is only weakly magnetic. Magnetite is black or brownish-black with a metallic luster, has a Mohs hardness of 5.5-6.5 and a black streak.
    Links: Top Ten Rocks/Stones, http://en.wikipedia.org/wiki/Loadstone,
  3. Quartz
    QuartzQuartz1
    Quartz is the 2nd most abundant mineral in the Earth’s continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz, several of which are semi-precious gemstones. Throughout the world, varieties of quartz have been since antiquity the most commonly used minerals in the making of jewelry and hardstone carvings. Maban or Mabain is a quartz material that is held to be magical in Australian Aboriginal mythology. It is the material from which the shamans and elders of indigenous Australia supposedly derive their magical powers.
    Links: Top Ten Skulls, Top Ten Skull Artifacts, http://en.wikipedia.org/wiki/Quartz,
  4. Rutile
    Rutile
    Rutile is a mineral composed primarily of titanium dioxide, TiO2. Rutile is the most common natural form of TiO2. Two rarer polymorphs of TiOare known: anatase (sometimes known by the obsolete name ‘octahedrite’), a tetragonal mineral of pseudo-octahedral habit; and brookite, an orthorhombic mineral. Rutile has among the highest refractive indices of any known mineral and also exhibits high dispersion. Natural rutile may contain up to 10% iron and significant amounts of niobium and tantalum. Rutile derives its name from the Latin rutilus, red, in reference to the deep red color observed in some specimens when viewed by transmitted light. Notable attributes of Rutile include an ability to absorb ultraviolet radiationb, as well as exhibiting a high dispersion and the highest refractive indice of any known mineral.
    Links: http://en.wikipedia.org/wiki/Rutile,
  5. Lapis Lazuli
    Lapis LazuliLapis Lazuli1Lapis Lazuli2
    Lapis lazuli is a relatively rare semi-precious stone that has been prized since antiquity for its intense blue color. Lapis lazuli was being mined in the Badakhshan province of Afghanistan as early as the 3rd millennium BC, and there are sources that are found as far east as in the region around Lake Baikal in Siberia. Trade in the stone is ancient enough for lapis jewelry to have been found at Predynastic Egyptian and ancient Sumerian sites, and as lapis beads at neolithic burials in Mehrgarh, the Caucasus, and even as far from Afghanistan as Mauritania. According to certain groups, lapis lazuli is associated with friendship and truth and generates positive energy in men. This gemstone is believed to keep away depression and negative thinking. It is also believed to be good for the eyes and useful in fever and stomach problems. Astrologers say that lapis lazuli provides happiness from family. It gives mental satisfaction. It generates will power and confidence in its natives. Its power is useful in marital relationships, helping to maintain a peaceful marital life.
    Links: http://en.wikipedia.org/wiki/Lapis_lazuli,
  6. Mica
    Mica
    The mica group of sheet silicate (phyllosilicate) minerals includes several closely related materials having highly perfect basal cleavage. All are monoclinic, with a tendency towards pseudohexagonal crystals, and are similar in chemical composition. The highly perfect cleavage, which is the most prominent characteristic of mica, is explained by the hexagonal sheet-like arrangement of its atoms. The word “mica” is derived from the Latin word mica, meaning “a crumb,” and probably influenced by micare, “to glitter.” commercially important micas are muscovite and phlogopite, which are used in a variety of applications. Mica’s value is based on several of its unique physical properties. The crystalline structure of mica forms layers that can be split or delaminated into thin sheets. These sheets are chemically inert, dielectric, elastic, flexible, hydrophilic, insulating, lightweight, platy, reflective, refractive, resilient, and range in opacity from transparent to opaque. Mica is stable when exposed to electricity, light, moisture, and extreme temperatures. It has superior electrical properties as an insulator and as a dielectric, and can support an electrostatic field while dissipating minimal energy in the form of heat; it can be split very thin (0.025 to 0.125 millimeters or thinner) while maintaining its electrical properties, has a high dielectric breakdown, is thermally stable to 500°C, and is resistant to corona discharge. Muscovite, the principal mica used by the electrical industry, is used in capacitors that are ideal for high frequency and radio frequency. Phlogopite mica remains stable at higher temperatures (to 900°C) and is used in applications in which a combination of high-heat stability and electrical properties is required.
    Links: http://en.wikipedia.org/wiki/Mica,
  7. Emerald
    EmeraldEmerald1Emerald2Emerald3
    Emerald is a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium and sometimes vanadium. Beryl has a hardness of 7.5–8 on the 10 point Mohs scale of mineral hardness. Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor.
    Links: Top Ten Emeralds, http://en.wikipedia.org/wiki/Emerald,
  8. Ruby
    RubyRuby1
    A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum (aluminium oxide). The red color is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires. The ruby is considered one of the four precious stones, together with the sapphire, the emerald, and the diamond. Among the natural gems only moissanite and diamond are harder, with diamond having a Mohs hardness of 10.0 and moissonite falling somewhere in between corundum (ruby) and diamond in hardness. Prices of rubies are primarily determined by color. The brightest and most valuable “red” called pigeon blood-red, commands a huge premium over other rubies of similar quality. After color follows clarity: similar to diamonds, a clear stone will command a premium, but a ruby without any needle-like rutile inclusions may indicate that the stone has been treated. Cut and carat (weight) are also an important factor in determining the price.
    Links: Top Ten Rubies, http://en.wikipedia.org/wiki/Ruby,
  9. Sapphire
    Sapphire
    Sapphire (Greek: sappheiros, “blue stone”) is a gemstone variety of the mineral corundum, an aluminium oxide (α-Al2O3). Trace amounts of other elements such as iron, titanium, chromium, copper or magnesium can give corundum blue, yellow, pink, purple, orange or greenish color. Chromium impurities in corundum yield a red tint, and the resultant gemstone is called a ruby. Sapphires are commonly worn in jewelry. Sapphires can be found naturally, by searching through certain sediments (due to their resistance to being eroded compared to softer stones), or rock formations, or they can be manufactured for industrial or decorative purposes in large crystal boules. Because of the remarkable hardness of sapphires, 9 in Mohs Scale, (and of aluminum oxide in general), sapphires are used in some non-ornamental applications, including infrared optical components, such as in scientific instruments; high-durability windows (also used in scientific instruments); wristwatch crystals and movement bearings; and very thin electronic wafers, which are used as the insulating substrates of very special-purpose solid-state electronics (most of which are integrated circuits).
    Links: Top Ten Sapphires, http://en.wikipedia.org/wiki/Sapphire,
  10. Chrysoberyl
    ChrysoberylChrysoberyl1Chrysoberyl2
    The mineral or gemstone chrysoberyl is an aluminate of beryllium with the formula BeAl2O4. The name chrysoberyl is derived from the Greek words chrysos and beryllos, meaning “a gold-white spar.” Despite the similarity of their names, chrysoberyl and beryl are two completely different gemstones. Chrysoberyl is the 3rd hardest frequently encountered natural gemstone and lies at 8.5 on the hardness scale, between corundum (9) and topaz (8). An interesting feature of its crystals are the cyclic twins called trillings. These twinned crystals have a hexagonal appearance, but are the result of a triplet of twins with each “twin” oriented at 120° to its neighbors and taking up 120° of the cyclic trilling. If only two of the three possible twin orientations are present, a “V”-shaped twin results. Ordinary chrysoberyl is yellowish-green and transparent to translucent. When the mineral exhibits good pale green to yellow color and is transparent, then it is used as a gemstone. The three main varieties of chrysoberyl are: ordinary yellow-to-green chrysoberyl, cat’s eye or cymophane, and alexandrite. Yellow-green chrysoberyl was referred to as “chrysolite” during the Victorian and Edwardian eras, which caused confusion since that name has also been used for the mineral olivine (“peridot” as a gemstone); that name is no longer used in the gemological nomenclature. Alexandrite, a strongly pleochroic (trichroic) gem, will exhibit emerald green, red and orange-yellow colors depending on viewing direction in partially polarized light. However, its most distinctive property is that it also changes color in artificial (tungsten/halogen) light compared to daylight. The color change from red to green is due to strong absorption of light in a narrow yellow portion of the spectrum, while allowing large bands of blue-greener and red wavelengths to be transmitted. Which of these prevails to give the perceived hue depends on the spectral balance of the illumination. Typically, alexandrite has an emerald-green color in daylight (relatively blue illumination of high color temperature) but exhibits a raspberry-red color in incandescent light (relatively yellow illumination). Cymophane is popularly known as “cat’s eye.” This variety exhibits pleasing chatoyancy or opalescence that reminds one of an eye of a cat. When cut to produce a cabochon, the mineral forms a light-green specimen with a silky band of light extending across the surface of the stone.
    Links: http://en.wikipedia.org/wiki/Chrysoberyl,
  11. Jade
    JadeJade1Jade2Jade3
    Jade is an ornamental stone. The term jade is applied to two different metamorphic rocks that are made up of different silicate minerals: Nephrite consists of a microcrystaline interlocking fibrous matrix of the calcium, magnesium-iron rich amphibole mineral series tremolite (calcium-magnesium)-ferroactinolite (calcium-magnesium-iron). The middle member of this series with an intermediate composition is called actinolite (the silky fibrous mineral form is one form of asbestos). The higher the iron content the greener the color. Jadeite is a sodium- and aluminium-rich pyroxene. The gem form of the mineral is a microcrystaline interlocking crystal matrix.
    Links: Top Ten Jade Artifacts,
  12. Links: Nature, Top Ten Metals, http://en.wikipedia.org/wiki/Mineral,