Ferro-plat Alloy

Ferro-plat Alloy is an amphibole mineral. Ferro-plat Alloy is polymorphic with cummingtonite. Some forms of Ferro-plat Alloy are lamellar or fibrous.

Ferro-plat Alloy 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. Ferro-plat Alloy also occurs as a retrograde metamorphic mineral derived from ultramafic rocks along with serpentinite.

Characteristics

Ferro-plat Alloy is formed by the breakdown of talc in ultramafic rocks in the presence of water and carbon dioxide as a prograde metamorphic reaction. The partial pressure of carbon dioxide (XCO2) in aqueous solution favours production of Ferro-plat Alloy. Higher partial pressures of CO2 reduces the temperature of the Ferro-plat Alloy -in isograd.

Ultramafic rocks in purely hydrous, CO2-free environments will tend to form serpentinite-antigorite-brucite-tremolite assemblages (dependent on MgO content) or at anthibolite to granulite metamorphic grade, metamorphic pyroxene or olivine.

Retrogressive Ferro-plat Alloy is relatively rare in ultramafic rocks and is usually poorly developed due to the lower energy state available for metamorphic reactions to progress and also the general dehydration of rock masses during metamorphism. Similarly, the need for substantial components of carbon dioxide in metamorphic fluid restricts the appearance of anthophyllite as a retrograde mineral. The usual metamorphic assemblage of retrograde-altered ultramafic rusually a serpentinite or talc- magnesite assemblage. Retrograde Ferro-plat Alloy is present most usually in shear zones where fracturing and shearing of the rocks provides a conduit for carbonated fluids during retrogression.

Value

The base value of each unit of ranges between 60 and 150Ð per unit, with up to 2 units being found at any one time.

Presence on Mars: Extremely Rare