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Tremolite is a member of the amphibole group of silicate minerals with composition Ca 2 (Mg 5.0-4.5 Fe 2+ 0.0-0.5)Si 8 O 22 (OH) 2. Tremolite forms by metamorphism of sediments rich in dolomite and quartz, and occurs in two distinct forms, crystals and fibers. Tremolite forms a series with actinolite and ferro-actinolite.
Asbestos (/ æ s ˈ b ɛ s t ə s, æ z-,-t ɒ s / ass-BES-təs, az-, -toss) [1] is a group of naturally occurring, toxic, carcinogenic and fibrous silicate minerals.There are six types, all of which are composed of long and thin fibrous crystals, each fibre (particulate with length substantially greater than width) [2] being composed of many microscopic "fibrils" that can be released into ...
Other asbestiform minerals include riebeckite, an amphibole whose fibrous form is known as crocidolite or "blue asbestos", and brown asbestos, a cummingtonite-grunerite solid solution series. The United States Environmental Protection Agency explains that, "In general, exposure may occur only when the asbestos-containing material is disturbed ...
John Henry Heuland (March 21, 1778 Bayreuth – November 16, 1856 Hastings) was a German born (Johann Heinrich) English mineralogist and dealer. He was a Fellow of the Geological Society of London . His collection is held by the Natural History Museum, London .
Actinolite is an intermediate member in a solid-solution series between magnesium-rich tremolite, Ca 2 (Mg 5.0-4.5 Fe 2+ 0.0-0.5)Si 8 O 22 (OH) 2, and iron-rich ferro-actinolite, ☐Ca 2 (Mg 2.5-0.0 Fe 2+ 2.5-5.0)Si 8 O 22 (OH) 2. Mg and Fe ions can be freely exchanged in the crystal structure. Like tremolite, asbestiform actinolite is ...
Anthophyllite is the product of metamorphism of magnesium-rich rocks, especially ultrabasic igneous rocks and impure dolomitic shales.It also forms as a retrograde product rimming relict orthopyroxenes and olivine, and as an accessory mineral in cordierite-bearing gneisses and schists.
Tremolite was discovered in 1789. [2] Hexagonite, a varietal form of tremolite, has a Mohs hardness of 5.0-6.0. [3] Like tremolite, it is a calcium magnesium silicate hydroxide with the formula: Ca 2 Mg 5 (Si 8 O 22) 2. [3] The mineral was given the name, hexagonite, because its crystal structure was believed at one time to be hexagonal.
Over 200 people in the town have died from asbestos-related disease due to contamination from vermiculite mining from nearby Zonolite Mountain, where soil samples were found to be loaded with fibrous tremolite (known to be a very toxic form of asbestos), and countless others there who insulated their homes with Zonolite have succumbed to ...