Armalcolita
Armalcolita is a mineral with formula (Fe,Mg)Ti₂O₅, in the Óxidos group. This specimen comes from Cantera La Aljorra, Los Nietos, Cartagena, Región de Murcia, España and joined the Terrium collection in 2025.
Description
Thumbnail with a microgeode; at its centre, a free-standing white spherule. The white aggregate is encircled by brown prismatic microcrystals—the armalcolite. Dense association of rare and more common species within barely 1 cm2.
History of this specimen
I numbered it 1969 because that was the year humanity first set foot on the Moon and brought back the first mineral identified beyond Earth, armalcolite.
About Armalcolita
Armalcolite was the first mineral discovered on the Moon. Its type locality is Mare Tranquillitatis, where Apollo 11 landed with Armstrong, Aldrin and Collins aboard. Its name is an acrostic formed from the surnames of these three astronauts. It is a titanium, iron and magnesium oxide, extremely rare on Earth, usually occurring as microcrystals or spherulitic aggregates.
About the locality
Cantera La Aljorra, in Cartagena (Murcia), sits on lamproitic volcanic rock (rich in potassium, titanium and iron). The microgeodes in this rock are time capsules that host a paragenesis of rare and exotic minerals (armalcolite, enstatite, tridymite, hyalite), the product of a deep, very specific magma chemistry that seldom reaches the Earth's surface.
Technical data
- Catalogue No.
- 1969
- Composition
- (Fe,Mg)Ti₂O₅
- Name
- Armalcolita
- Group
- Óxidos
- Category
- Meritum Persé
- Matrix
- Lamproíta
- Associations
- pseudobrookita enstatita tridimita calcita sanidina ópalo
- Mine
- Cantera La Aljorra
- District / Municipality
- Los Nietos
- Province
- Cartagena
- Region
- Región de Murcia
- Country
- España
- Size (cm)
- 1.2 x 1.3 x 1.3
- Weight
- 1.5 g
- Acquired
- 2025
- Etymology
- Named in 1970 from an acronym of the surnames of the three Apollo 11 astronauts who brought it from the Moon: ARMstrong, ALdrin and COLlins.
- Quality
- Muy buena
- Value trend
- Estable
Related specimens
- Abellaíta — España
- Abernathyita — España
- Abernathyita — España
- Abernathyita — España
- Aerenita — España
- Aerinita (fibrosa) — España
- Analcima — España
- Analcima — España