Calcita Manganocalcita
Calcita is a mineral with formula CaCO₃ + Mn, in the Carbonatos group. This specimen comes from Mina Manolita, La Unión, Cartagena, Región de Murcia, España and joined the Terrium collection in 2001.
Description
The Barnacles. Aggregate of scalenohedral calcite crystals with manganiferous inclusions, probably chalcophanite, with a morphology recalling a colony of "barnacles", both in the aggregate and at the upper terminations. Good lustre and an olive-brown, submetallic tone.
About Calcita
A modest but excellent piece for the rarity of its habit and colouration, probably caused by chalcophanite, a hydrated manganese oxide with zinc. Chalcophanite has metallic to submetallic lustre and iron-black to dark-brown colour, typically occurring as laminae or aggregates that markedly modify the surface appearance of calcite.
About the locality
Manolita Mine, also cited as Calcitas Viejas Mine, at El Puntal, within the Sierra Minera de Cartagena-La Unión. The alternative name is not incidental: among collectors the locality became especially associated with its calcites, highly varied in habit, texture and appearance, and it is listed as such in several mineralogical references.
Technical data
- Catalogue No.
- 0363
- Composition
- CaCO₃ + Mn
- Name
- Calcita
- Variety
- Manganocalcita
- Group
- Carbonatos
- Category
- Meritum Persé
- Associations
- calcofanita
- Mine
- Mina Manolita
- District / Municipality
- La Unión
- Province
- Cartagena
- Region
- Región de Murcia
- Country
- España
- Size (cm)
- 5 x 4 x 3
- Weight
- 44.1 g
- Acquired
- 2001
- Ex-collection
- Ángel García
- Etymology
- From the Latin "calx", lime, an etymological root common to calcite, limestone and calcium.
- 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