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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 ...
Three polytypes of chrysotile are known. [8] These are very difficult to distinguish in hand specimens, and polarized light microscopy [6] must normally be used. Some older publications refer to chrysotile as a group of minerals—the three polytypes listed below, and sometimes pecoraite as well—but the 2006 recommendations of the International Mineralogical Association prefer to treat it as ...
Asbestiform is a crystal habit. It describes a mineral that grows in a fibrous aggregate of high tensile strength , flexible, long, and thin crystals that readily separate. [ 1 ] The most common asbestiform mineral is chrysotile , commonly called "white asbestos ", a magnesium phyllosilicate part of the serpentine group .
Organizations such as the Asbestos Disease Awareness Organization have supported the move as the olive green rock is a source of chrysotile, a form of asbestos that can cause mesothelioma and other forms of cancer. Geologists have rallied to oppose the bill, arguing that there is no way to be harmed from casual exposure to serpentine. [79]
Serpentine minerals are polymorphous, meaning that they have the same chemical formulae, but the atoms are arranged into different structures, or crystal lattices. [7] Chrysotile , which has a fibrous habit , is one polymorph of serpentine and is one of the more important asbestos minerals.
Erionite forms brittle, wool-like fibrous masses in the hollows of rock formations and has an internal molecular structure similar to chabazite. This mineral is likely as toxic as asbestos; however, erionite is not currently regulated by the U.S. Environmental Protection Agency and there are no occupational exposure limits for erionite fibers.
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.
Serpentinite is a metamorphic rock composed predominantly of serpentine group minerals formed by serpentinization of mafic or ultramafic rocks. The ancient origin of the name is uncertain; it may be from the similarity of its texture or color to snake skin. [1] Greek pharmacologist Dioscorides (AD 50) recommended eating this rock to prevent ...