To explore the world of rocks,minerals,and crystals. Thier scientific make-up,mythology,healing powers,physical uses.Will post weekly/bi-weekly/monthly new minerals and references. All of my references will come from the following, 1)Webster's New World Dictionary and Thesaurus 2)Encylopedia of Minerals, 2nd edition-Willard L.Roberts-Thomas J. Campbell-George R. Rapp Jr. 3)Directory of Healing Crystals -Cassandra Eason. Cassandra isan international author and broadcaster on all aspects of crystals,folklore and the paranormal. 4)Crystal Therapy-Doreen Virtue,Ph.D and Judith Lukomski
Gypsum occurs in nature as flattened and often twinnedcrystals and transparent cleavable masses called selenite. It may also occur in a silky, fibrous form, in which case it is commonly called satin spar. Finally it may also be granular or quite compact. In hand-sized samples, it can be anywhere from transparent to opaque. A very fine-grained white or lightly tinted variety of gypsum is called alabaster, and is prized for ornamental work of various sorts. In arid areas, gypsum can occur in a flower-like form typically opaque with embedded sand grains called desert rose. Up to the size of 11 m long, gypsum forms some of the largest crystals found in nature, in the form of selenite.[4]
Gypsum is a common mineral, with thick and extensive evaporite beds in association with sedimentary rocks. Deposits are known to occur in strata from as early as the Permian age.[5] Gypsum is deposited in lake and sea water, as well as in hot springs, from volcanic vapors, and sulfate solutions in veins. Hydrothermalanhydrite in veins is commonly hydrated to gypsum by groundwater in near surface exposures. It is often associated with the minerals halite and sulfur.
The word gypsum is derived from the Greek word γύψος, "chalk" or "plaster".[6] Because the gypsum from the quarries of the Montmartre district of Paris has long furnished burnt gypsum used for various purposes, this material has been called plaster of Paris. It is also used in foot creams, shampoos and many other hair products.
Gypsum is moderately water-soluble (~2.0 – 2.5 g/L at 25 °C)[7] and, in contrast to most other salts, it exhibits a retrograde solubility, becoming less soluble at higher temperatures. As for anhydrite, its solubility in saline solutions and in brines is also strongly dependent on NaCl concentration.[7] Because gypsum dissolves over time in water, gypsum is rarely found in the form of sand. However, the unique conditions of the White Sands National Monument in the US state of New Mexico have created a 710-square-kilometer (270 sq mi) expanse of white gypsum sand, enough to supply the construction industry with drywall for 1,000 years.[8] Commercial exploitation of the area, strongly opposed by area residents, was permanently prevented in 1933 when president Herbert Hoover declared the gypsum dunes a protected national monument.
Crystals of gypsum up to 11 meters (36 ft) long have been found in the caves of the Naica Mine of Chihuahua, Mexico. The crystals thrived in the cave's extremely rare and stable natural environment. Temperatures stayed at 58 °C, and the cave was filled with mineral-rich water that drove the crystals' growth. The largest of those crystals weighs 55 short tons (50,000 kg) and is around 500,000 years old.[11][12]
Synthetic gypsum is recovered via flue gas desulfurization at some coal-fired electric power plants. It can be used interchangeably with natural gypsum in some applications.
Fertilizer and soil conditioner. In the late 18th and early 19th century, Nova Scotia gypsum, often referred to as plaster, was a highly sought fertilizer for wheat fields in the United States. It is also used in ameliorating sodic soils.[15]
A wood substitute in the ancient world; for example, when wood became scarce due to deforestation on Bronze AgeCrete, gypsum was employed in building construction at locations where wood was previously used.[16]
A tofu (soy bean curd) coagulant, making it ultimately a major source of dietary calcium, especially in Asian cultures which traditionally use few dairy products.
In the medieval period it was mixed, by scribes and illuminators, with lead carbonate (powdered white lead) to make gesso which was applied to illuminated letters and gilded with gold in illuminated manuscripts.
The spinels are any of a class of minerals of general formulation A2+B23+O42- which crystallise in the cubic (isometric) crystal system, with the oxide anions arranged in a cubic close-packedlattice and the cations A and B occupying some or all of the octahedral and tetrahedral sites in the lattice. A and B can be divalent, trivalent, or quadrivalent cations, including magnesium, zinc, iron, manganese, aluminium, chromium, titanium, and silicon. Although the anion is normally oxide, structures are also known for the rest of the chalcogenides. A and B can also be the same metal under different charges, such as the case in Fe3O4 (as Fe2+Fe23+O42-).
Spinel crystallizes in the isometric system; common crystal forms are octahedra, usually twinned. It has an imperfect octahedral cleavage and a conchoidal fracture. Its hardness is 8, its specific gravity is 3.5-4.1 and it is transparent to opaque with a vitreous to dull luster. It may be colorless, but is usually various shades of red, blue, green, yellow, brown or black. There is a unique natural white spinel, now lost, that surfaced briefly in what is now Sri Lanka. Some spinels are among the most famous gemstones: Among them is the Black Prince's Ruby and the 'Timur ruby' in the British Crown Jewels, and the 'cote de Bretagne' formerly from the French Crown jewels. The Samarian Spinel is the largest known spinel in the world, weighing 500 carats (100 g).
The transparent red spinels were called spinel-rubies or balas-rubies. In the past, before the arrival of modern science, spinels and rubies were equally known as rubies. After the 18th century the word ruby was only used for the red gem variety of the mineral corundum and the word spinel became used. "Balas" is derived from Balascia, the ancient name for Badakhshan, a region in central Asia situated in the upper valley of the Kokcha River, one of the principal tributaries of the Oxus River. The Badakshan Province was for centuries the main source for red and pink spinels.
True spinel has long been found in the gemstone-bearing gravel of Sri Lanka and in limestones of the Badakshan Province in nowadays Afghanistan and of Mogok in Burma. Recently gem quality spinels were also found in the marbles of Luc Yen (Vietnam), Mahenge and Matombo (Tanzania), Tsavo (Kenya) and in the gravels of Tunduru (Tanzania) and Ilakaka (Madagascar). Spinel is found as a metamorphic mineral, and also as a primary mineral in rare mafic igneous rocks; in these igneous rocks, the magmas are relatively deficient in alkalis relative to aluminium, and aluminium oxide may form as the mineral corundum or may combine with magnesia to form spinel. This is why spinel and ruby are often found together.
Spinel, (Mg,Fe)(Al,Cr)2O4, is common in peridotite in the uppermost Earth's mantle, between 450 km (where olivine is metamorphosed to spinel) to 670 km kilometers or so; below that depth, the spinel is oxidised. At depths significantly shallower than the Moho, calcic plagioclase is the more stable aluminous mineral in peridotite.
Normal spinel structures are usually cubic closed-packed oxides with one octahedral and two tetrahedral sites per oxide. The tetrahedral points are smaller than the Octahedral points. B3+ ions occupy the octahedral holes because of a charge factor, but can only occupy half of the octahedral holes. A2+ ions occupy 1/8th of the tetrahedral holes. This maximises the lattice energy if the ions are similar in size. A common example of a normal spinel is MgAl2O4.
Inverse spinel structures however are slightly different in that one must take into account the crystal field stabilization energies (CFSE) of the transition metals present. Some ions may have a distinct preference on the octahedral site which is dependent on the d-electron count. If the A2+ ions have a strong preference for the octahedral site, they will force their way into it and displace half of the B3+ ions from the octahedral sites to the tetrahedral sites. If the B3+ ions have a low or zero octahedral site stabilization energy (OSSE), then they have no preference and will adopt the tetrahedral site. A common example of an inverse spinel is Fe3O4, if the Fe2+ (A2+) ions are d6 high-spin and the Fe3+ (B3+) ions are d5 high-spin.
For many years, crystal field theory was invoked to explain the distribution of the cations within the spinels. As the octahedral and tetrahedral sites in the lattice generate different amounts of CFSE, it was argued that the arrangement of the two types of cation that generated the most CFSE would be the most stable. However, this idea was challenged by Burdett and co-workers, who showed that a better treatment used the relative sizes of the s and p atomic orbitals of the two types of atom to determine their site preference.[4] This is because the dominant stabilizing interaction in the solids is not the crystal field stabilization energy generated by the interaction of the ligands with the d-electrons, but the σ-type interactions between the metal cations and the oxide anions. This rationale can explain anomalies in the spinel structures that crystal-field theory cannot, such as the marked preference of Al3+ cations for octahedral sites or of Zn2+ for tetrahedral sites - using crystal field theory would predict that both have no site preference. Only in cases where this size-based approach indicates no preference for one structure over another do crystal field effects make any difference — in effect they are just a small perturbation that can sometimes make a difference, but which often do not.
Synthetic spinel was accidentally produced in the middle of the 18th century, and has been more recently described in scientific publications in 2000 and 2004.[5]
Nestling up to a cauldron of pressurized, molten rock is almost never a good idea. But in Mexico's Naica mine, the payoff is worth the risk.
About 900 feet below the surface, there is a chamber filled with gypsum. It's the same stuff that goes in the drywall in your house, only in Naica it spent half a million years parboiling in a chamber filled with magma-heated water.
Suddenly miners showed up and started pumping the mineral-rich broth out to get at valuable silver and lead deposits nearby. The result is a cavern filled with crystals 36 feet long and weighing in at up to 55 tons, easily the largest in the world.
Last Fall, adventurer and filmmaker George Kourounis traveled to Naica to see the incredible “Crystal Cave of Giants” for himself. Though there's little risk of eruption from the nearby magma chamber, the cave itself is still deadly hot – over 120 Fahrenheit with about 90 percent humidity. People are only allowed in without cooling suits for a few minutes at a time.
"When we first arrived at the Naica mine, Manuel and his crew took us inside without wearing the special cooling suits. This was in order to get us used to what REAL heat is like. There is a steel door protecting the cave and as soon as you pass through it, the temperature hits you like a truck.
But as soon as you get your first glimpse of the incredible crystals, you want to keep going deeper. We were inside for only 14 minutes, which was pushing the danger limits without cooling suits. When we exited, the staging area was a "cool" 41 Celsius. My heart was pounding and I was completely soaked in sweat, my shirts, pants, socks & boots... Everything. All we could do was sit, drink and rest."
Cooling suits – vests of frozen gel packs surrounded by insulation, plus a backpack that supplies the wearer with chilled air to breathe – allow people to remain in the mine for close to an hour. Kourounis and his crew took the opportunity to snap these incredible images as well as shoot some video.
Of his experience visiting the crystal cave, Kourounis writes:
"I've never seen such a spectacular place. It was like setting foot on a new planet. Many of the crystals were so large that I couldn't even wrap my arms around them and the terrain was so difficult to walk on that we had to be extremely cautious not to slip and fall. Doing so would could get you impaled on a sharp crystal and would require a dangerous and difficult rescue."
Sadly, once the silver in Naica runs out, miners will likely turn the pumps off again. The chamber will fill with water, the crystals will once again be among Earth's vast, inaccessible depths.
Hi everyone. Sorry for the delay! Needed to work through some ugly times that there was no choice involved but to accept it !! Most of me is back !Im going to pick right up from where i left off.History and mythology,uses , etc... Im going to start with Clear Quartz and move into each one of the ones listed in the three breakdowns ! Hope you enjoy ! There will also be more deffinitions inorder for better understanding. Also at the end of clear quartz i am going to do a section on the different crystal formations and thier attributes and characteristics .Peace, Mark PS Thank you all for your patiance and understanding as well as the incredible amount of TLC and support i recieved during this tough time !! TY TY TY TY
