Graftonite
Encyclopedia
Graftonite is an iron
(II), manganese
, calcium
phosphate mineral
with formula: (Fe2+,Mn,Ca)3(PO4)2. It forms lamellar to granular translucent brown to red-brown to pink monoclinic prismatic crystals. It has a vitreous luster with a Mohs hardness of 5 and a specific gravity
of 3.67 to 3.7.
It was first described from its type locality
of Melvin Mountain in the town of Grafton
, in Grafton County, New Hampshire
.
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
(II), manganese
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
, calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
phosphate mineral
Phosphate minerals
Phosphate minerals are those minerals that contain the tetrahedrally coordinated phosphate anion along with the freely substituting arsenate and vanadate...
with formula: (Fe2+,Mn,Ca)3(PO4)2. It forms lamellar to granular translucent brown to red-brown to pink monoclinic prismatic crystals. It has a vitreous luster with a Mohs hardness of 5 and a specific gravity
Specific gravity
Specific gravity is the ratio of the density of a substance to the density of a reference substance. Apparent specific gravity is the ratio of the weight of a volume of the substance to the weight of an equal volume of the reference substance. The reference substance is nearly always water for...
of 3.67 to 3.7.
It was first described from its type locality
Type locality (geology)
Type locality , also called type area or type locale, is the where a particular rock type, stratigraphic unit, fossil or mineral species is first identified....
of Melvin Mountain in the town of Grafton
Grafton, New Hampshire
Grafton is a town in Grafton County, New Hampshire, United States. The population was 1,340 at the 2010 census.- History :Originally granted in 1761, and re-granted in 1769, Grafton, like the county it resides in, takes its name from Augustus FitzRoy, 3rd Duke of Grafton, a relative of colonial...
, in Grafton County, New Hampshire
Grafton County, New Hampshire
Grafton County is a county located in the U.S. state of New Hampshire. As of the 2010 census, the population was 89,118. Its county seat is North Haverhill, which is a village within the town of Haverhill. Until 1972, the county courthouse and other offices were located in downtown Woodsville, a...
.