Arrojadite-(KFe)

Arrojadite-(KFe) is an uncommon mineral that is phosphate. It was named to honour Miguel Arrojado Ribeiro Lisbôa (1872–1932), an engineer that is Brazilian geologist and geographer. He gained renown that is international his studies of manganese and monazitic sands. In 2005 Arrojadite’s name ended up being changed to Arrojadite-(KFe) by the International Mineralogical Association (IMA) as part of the modification of the nomenclature of the Arrojadite Group to chemically distinguish it from the other people of the group. Lots of the other people of the group have the basis that is same with various suffixes added to denote their unique chemical structures. Listed here are some of the users associated with Arrojadite Group: Arrojadite-(BaFe), Arrojadite-(BaNa), Arrojadite-(KFe), Arrojadite-(KFeNa), Arrojadite-(KNa), Arrojadite-(NaFe), Arrojadite-(PbFe), Arrojadite-(SrFe).

Arrojadite is seldom if ever, discovered as transparent crystals adequate for faceting. It’s typically discovered as translucent to opaque, cleavable masses. Gems are faceted from this material solely as a collector that is an uncommon gem. The most effective specimens for mineral collectors come from the find in 2001 at the Big Fish River–Rapid Creek area, Dawson Mining District, Yukon Territory, Canada. This supply has produced some of this richest example of Arrojadite ever found.

Circulation: In Brazil, from the Serra Branca pegmatite, 13 km south of Pedra Lavrada, Picuí, Paraíba; into the Énio pegmatite mine, northeast of Galiléia, and the Sapucaia pegmatite mine, about 50-kilometre east-southeast of Governador Valadares, Minas Gerais. In the United States, in brand new Hampshire, through the G.E. Smith mine, Newport, Sullivan County, as well as the Rice, Nancy #2, and Palermo #1 mines, near North Groton, Grafton County; in South Dakota, from the Nickel Plate and White Cap mines, near Keystone, Pennington County, plus in the Victory mine, four northeast that is km of, Custer County. From the Big Fish River–Rapid Creek area, Yukon Territory, Canada. Into the Mangualde pegmatite, near Mesquitela, Portugal. From Glenbuchat, Aberdeenshire, Scotland. In the Norrö pegmatite, on Rånö Island, Sweden. At Sidi-Bou-Kritcha, Morocco. In Zimbabwe, from Ruwanzi Ranch, Karoi East, Miami, and on the Star Twin, Pearl and Chiwya claims, Urungwe district. In the Buranga pegmatite, near Gatumba, Rwanda.

 

Chemical Formula: KNa4Ca(Fe2+,Mn2+)14Al(PO4)12(OH)2
Potassium Sodium Calcium Iron Manganese Aluminum Phosphate Hydroxide
Molecular Weight: 2,033.08 gm
Composition: Potassium 1.92 % K 2.32 % K2O
Sodium 4.52 % Na 6.10 % Na2O
Calcium 1.97 % Ca 2.76 % CaO
Magnesium 2.39 % Mg 3.96 % MgO
Manganese 10.81 % Mn 13.96 % MnO
Aluminum 1.33 % Al 2.51 % Al2O3
Iron 19.23 % Fe 24.74 % FeO
Phosphorus 18.28 % P 41.89 % P2O5
Hydrogen 0.12 % H 1.11 % H2O
Oxygen 38.95 % O
Fluorine 0.47 % F 0.47 % F
 —  % F -0.20 % -O=F2
100.00 % 99.61 % = TOTAL OXIDE

 

Crystallography: Monoclinic – Domatic
Crystal Habit: As cleavable masses, to 15 cm
Twinning: None

 

Cleavage: Good on {100}, poor on {102}
Fracture: Uneven/Irregular to Subconchoidal
Tenacity: Brittle
Moh’s Hardness: 5.0
Density: 3.50 – 3.60 (g/cm3)
Luminescence: None
Radioactivity: Barely Detectable; GRapi = 26.90 (Gamma Ray American Petroleum Institute Units)

 

Color: Dark green, bottle-green, yellowish green, brownish yellow,
Transparency: Translucent
Luster: Vitreous to greasy
Refractive Index: 1.664 – 1.675  Biaxial ( + )
Birefringence: 0.011
Dispersion: Strong, r < v
Pleochroism: Visible; X = colorless; Y = colorless to pale green; Z = pale yellow-green