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armalcolite
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armalcolite

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Also known as IMA1970-006

Armalcolite () is a titanium-rich mineral with the chemical formula (Mg,Fe2+)Ti2O5. It was first found at Tranquility Base on the Moon in 1969 during the Apollo 11 mission, and is named for Armstrong, Aldrin and Collins, the three Apollo 11 astronauts. Together with tranquillityite and pyroxferroite, it is one of three new minerals that were discovered on the Moon. Armalcolite was later identified at various locations on Earth and has been synthesized in the laboratory. (Tranquillityite and pyroxferroite were also later found at various locations on Earth). The synthesis requires low pressures

Key facts

Mineral.name
Armalcolite
Mineral.category
Titanium mineral
Mineral.image
Armalcolite - Wat Lu Mine, Mogok, Myanmar.jpg
Mineral.caption
Armalcolite from Myanmar (grain size 5 mm)
Mineral.formula
(Mg,Fe2+)Ti2O5
Mineral.IMAsymbol
Arm
Mineral.strunz
4.CB.15
Mineral.system
Orthorhombic
Mineral.class
Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
Mineral.symmetry
Bbmm
Mineral.unit cell
a = 9.743(30) b = 10.023(20) c = 3.738(30) [Å], Z = 5
Mineral.color
Gray to tan in reflection, opaque
Mineral.mohs
<5
Mineral.luster
Metallic
Mineral.opticalprop
Biaxial
Mineral.gravity
4.64 g/cm3 (measured)

via Wikipedia infobox

Wikidata facts

Named after
Michael Collins
Image
Armalcolite Tomeik.jpg
Show 8 more facts
IMA Mineral Symbol
Arm
chemical formula
(Mg,Fe²⁺)Ti₂O₅
Strunz 8th edition (series ID, updated)
IV/C.11
Nickel-Strunz '10th ed', review of (9th ed/ 2009 update)
4.CB.15
Commons category
Armalcolite
Nickel-Strunz 9th edition (updated 2009)
4.CB.15
type locality (geology)
Statio Tranquillitatis
Sources (2)

via Wikidata · CC0

~8 min read

Encyclopedic overview

6 sections
Contents
  • Occurrence
  • Synthesis
  • Properties
  • See also
  • References
  • External links

Armalcolite () is a titanium-rich mineral with the chemical formula (Mg,Fe2+)Ti2O5. It was first found at Tranquility Base on the Moon in 1969 during the Apollo 11 mission, and is named for Armstrong, Aldrin and Collins, the three Apollo 11 astronauts. Together with tranquillityite and pyroxferroite, it is one of three new minerals that were discovered on the Moon. Armalcolite was later identified at various locations on Earth and has been synthesized in the laboratory. (Tranquillityite and pyroxferroite were also later found at various locations on Earth). The synthesis requires low pressures, high temperatures and rapid quenching from about 1,000&nbsp;°C to the ambient temperature. Armalcolite breaks down to a mixture of magnesium-rich ilmenite and rutile at temperatures below 1,000&nbsp;°C, but the conversion slows down with cooling. Because of this quenching requirement, armalcolite is relatively rare and is usually found in association with ilmenite and rutile, among other minerals.

==Occurrence== thumb|left|The Apollo 11 crew, after whom Armalcolite is named. Left to right are [[Neil Armstrong, Michael Collins, and Buzz Aldrin.]]

Excerpted from Wikipedia’s “armalcolite” article, available under the CC BY-SA 4.0 licence.

Gallery (4)