Alpha-hyblite is a porcelain-white, hydrous acidic sulfosilicate of thorium, with minor uranium, iron, and lead. It is an alteration product of thorite, first described from Hybla, Ontario, Canada.
🌍 Origins and Naming
- Name Origin: From Hybla, Ontario, Canada, where it was first identified.
- Discovery: Documented in the early 20th century during studies of thorite alteration.
- Polymorphism: Exists alongside beta-hyblite, another alteration phase of thorite.
🔬 Chemical and Structural Properties
- Formula: Approximate composition is Th-sulfosilicate with variable U, Fe, Pb.
- Nature: Hydrous, acidic sulfosilicate.
- Crystal System: Isotropic (lacks long-range crystalline order).
- Color: Porcelain-white, pearly luster.
- Habit: Soft alteration crusts or coatings on thorite crystals.
- Hardness: Very brittle, softer than thorite.
- Stability: Secondary mineral formed by alteration rather than primary crystallization.
⚙️ Geological Occurrence
- Formation: Alteration of thorite in fractured zones of pegmatites.
- Localities:
- Hybla, Ontario, Canada (type locality).
- Found in association with uranothorite and feldspar in pegmatitic rocks.
- Associated Minerals: Thorite, uranothorite, feldspar, other secondary thorium phases.
📖 Scientific and Collector Significance
- Petrology: Important for understanding alteration pathways of thorium minerals.
- Collectors: Extremely rare, usually only found as alteration coatings; valued academically rather than aesthetically.
- Economic Note: No industrial use; thorium content is of scientific interest but not extractable from such alteration products.
⚠️ Safety Considerations
Contains thorium and uranium, both radioactive. Specimens should be handled with care, stored safely, and not used for casual display without precautions.
✨ Conclusion
Alpha-hyblite is a rare thorium sulfosilicate alteration product, porcelain-white and isotropic, first described from Hybla, Ontario. It is scientifically significant for illustrating thorite alteration but remains a mineralogical curiosity rather than an economic resource.
In short: Alpha-hyblite = porcelain-white thorium sulfosilicate, alteration of thorite, rare, first found at Hybla, Ontario.
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