Gregoryite
Encyclopedia
Gregoryite is an anhydrous
carbonate
that is rich in potasium and sodium
(examples of geochemical composition: [(Na2,K2,Ca)CO3], [Na0.78K0.05][Ca0.17CO3]). It is one of the two main ingredients of natrocarbonatite
, found naturally in the lava of Ol Doinyo Lengai
volcano, the other being nyerereite
.
Because of its unhydrous nature, gregoryite reacts quickly with the environment, causing the dark lava to be converted to white substance within hours.
Gregoryite was named after the British geologist and author John Walter Gregory
, who studied the East African Rift Valley
.
Anhydrous
As a general term, a substance is said to be anhydrous if it contains no water. The way of achieving the anhydrous form differs from one substance to another...
carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
that is rich in potasium and sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
(examples of geochemical composition: [(Na2,K2,Ca)CO3], [Na0.78K0.05][Ca0.17CO3]). It is one of the two main ingredients of natrocarbonatite
Natrocarbonatite
Natrocarbonatite is a rare carbonatite lava which erupts from the Ol Doinyo Lengai volcano in Tanzania within the Great Rift Valley of eastern Africa. Whereas most lavas are rich in silicate minerals, the natrocarbonatite lavas of Ol Doinyo Lengai are rich in the rare sodium and potassium carbonate...
, found naturally in the lava of Ol Doinyo Lengai
Ol Doinyo Lengai
Ol Doinyo Lengai is an active volcano located in the north of Tanzania and is part of the volcanic system of the Great Rift Valley in Eastern Africa. It is located in the eastern Rift Valley, south of both Lake Natron and Kenya. It is unique among active volcanoes in that it produces...
volcano, the other being nyerereite
Nyerereite
Nyerereite is a very rare sodium calcium carbonate mineral with formula Na2Ca2. It forms colorless, platey pseudohexagonal orthorhombic crystals that are typically twinned. It has a specific gravity of 2.54 and indices of refraction of nα=1.511, nβ=1.533 and nγ=1.535. Nyerereite is not stable in...
.
Because of its unhydrous nature, gregoryite reacts quickly with the environment, causing the dark lava to be converted to white substance within hours.
Gregoryite was named after the British geologist and author John Walter Gregory
John Walter Gregory
John Walter Gregory, FRS, was a British geologist and explorer, known principally for his work on glacial geology and on the geography and geology of Australia and East Africa.-Early life:...
, who studied the East African Rift Valley
East African Rift
The East African Rift is an active continental rift zone in eastern Africa that appears to be a developing divergent tectonic plate boundary. It is part of the larger Great Rift Valley. The rift is a narrow zone in which the African Plate is in the process of splitting into two new tectonic plates...
.