Yeso
Yeso is a mineral with formula CaSO₄·2H₂O, in the Sulfatos group. This specimen comes from Balsa depositaria, Mina La Unión, La Unión, Cartagena, Región de Murcia, España and joined the Terrium collection in 2025.
Description
A long acicular gypsum crystal, translucent and amber-orange in tone, showing elongated prismatic growth. Internal transparency reveals point-like inclusions, with a visible swallowtail twin and basal epitaxial growth. Two crystallisation phases confer internal clarity and a warm external hue.
History of this specimen
Gift from a field collector during the La Unión Mineral Show 2025. It went unnoticed for months until, when I created the "Estélites Acicularia" section, it claimed a prominent place for its form and proportion.
About Yeso
Gypsum is a hydrated calcium sulphate that crystallises in tabular, acicular or twinned habits. In the depositary pond, the slow evaporation of sulphate-rich water favours the formation of clear, slender and well-defined crystals like this specimen.
About the locality
The depositary pond at La Unión formed from the accumulation of mine waters loaded with sulphates, creating conditions ideal for the development of high-purity gypsum crystals. The area is known among collectors for producing very aesthetic and distinctive specimens.
Technical data
- Catalogue No.
- 0158
- Composition
- CaSO₄·2H₂O
- Name
- Yeso
- Group
- Sulfatos
- Category
- Estélites
- Mine
- Balsa depositaria, Mina La Unión
- District / Municipality
- La Unión
- Province
- Cartagena
- Region
- Región de Murcia
- Country
- España
- Size (cm)
- 9.5 x 0.9 x 0.3
- Weight
- 13 g
- Acquired
- 2025
- Etymology
- From the Greek "gypsos", meaning "plaster" or "chalk", in reference to its historic use as a material for construction and sculpture.
- Quality
- Muy buena
- Value trend
- Estable
Related specimens
- Abellaíta — España
- Abernathyita — España
- Abernathyita — España
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- Aerenita — España
- Aerinita (fibrosa) — España
- Analcima — España
- Analcima — España