Čejkaite
Čejkaite is a mineral with formula Na₄(UO₂)(CO₃)₃, in the Carbonatos de uranilo group. This specimen comes from Mina Eureka, Castell-estaó, Lleida, Catalunya, España.
Description
Pale yellow pulverulent patches on grey-pink matrix; earthy efflorescent texture with no visible crystals; slight earthy lustre and yellow dispersion.
History of this specimen
It comes from the Vandenbroucke Museum (Waregem, Belgium), a very large private collection occupying 750 m² founded by Arthur "Tuur" Vandenbroucke, an industrialist in the natural-stone sector. In 1999, the bankruptcy of his company sealed the fate of the museum as well, regrettably treated as just another company asset. After the 2002 court auction, the German expert Christian Rewitzer (co-author of the Atlas de Minerales de España) recovered this specimen and incorporated it into his systematic archive. That is how it reached me.
About Čejkaite
Neoformation. A sodium uranyl carbonate (sodium uranyl tricarbonate). It crystallises in the triclinic system and forms by efflorescence in alteration environments, usually on calcite.
About the locality
The Eureka mine (Vall Fosca, Lleida) is one of the few localities in Spain that produce rare uranyl carbonates such as čejkaite, abellaite and andersonite in supergene environments on calcitic veins. This locality—never a mine but an area of uranium prospecting—was the second place in the world where Joan Abella and Joan Viñals documented this very rare species. Until 2008, čejkaite had only been found in the Geschieber lode of the Svornost mine at Jáchymov in the Czech Republic, discovered in 1997.
Technical data
- Catalogue No.
- 0118
- Composition
- Na₄(UO₂)(CO₃)₃
- Name
- Čejkaite
- Group
- Carbonatos de uranilo
- Category
- Núcleus Ardens
- Mine
- Mina Eureka
- District / Municipality
- Castell-estaó
- Province
- Lleida
- Region
- Catalunya
- Country
- España
- Size (cm)
- 4 x 2 x 1
- Weight
- 12 g
- Ex-collection
- Vandenbroucke Museum Collection → Christian Rewitzer
- Etymology
- Named in honour of Jiří Čejka (b. 1929), eminent mineralogist at the National Museum in Prague and a world authority on the chemistry of uranium minerals.
- Quality
- Buena
- Value trend
- Estable
Related specimens
- Abellaíta — España
- Abernathyita — España
- Abernathyita — España
- Abernathyita — España
- Aerenita — España
- Aerinita (fibrosa) — España
- Analcima — España
- Analcima — España