Amatrice

Amatrice is an obsolete mineral name that was historically applied to a variety of scapolite. It is not recognized today as a distinct mineral species by the International Mineralogical Association (IMA).

🌍 Origins and Naming

• Name Origin: From Amatrice, a town in Lazio, Italy, where the mineral variety was first described.
• Status: Discredited; modern mineralogy treats “amatrice” as a synonym for scapolite rather than a separate species.
• Historical Context: In the 19th century, local or compositional variants of scapolite were often given distinct names before structural and chemical analysis clarified their identity.

🔬 Chemical and Structural Properties (Scapolite Group)

• General Formula: (Na,Ca)₄(Si,Al)₁₂O₂₄
• Mineral Group: Feldspathoid group (scapolite series: marialite ↔ meionite).
• Crystal System: Tetragonal.
• Color: White, gray, pink, violet, or yellow depending on impurities.
• Habit: Prismatic crystals, granular aggregates, massive forms.
• Hardness: ~5–6 on Mohs scale.
• Specific Gravity: ~2.6–2.8.
• Luster: Vitreous.

⚙️ Geological Occurrence

• Environment: Found in metamorphic rocks (marbles, gneisses) and some igneous rocks.
• Associated Minerals: Calcite, diopside, feldspar, quartz.
• Localities: Amatrice (Italy), and scapolite-bearing rocks worldwide.

📖 Scientific and Collector Significance

• Petrology: Scapolite minerals are important indicators of metamorphism and metasomatism.
• Collectors: Crystals can be attractive, especially violet scapolite varieties, though “amatrice” as a name is obsolete.
• Industrial Uses: Scapolite has limited industrial use; occasionally cut as a gemstone.

✨ Conclusion

Amatrice is an obsolete synonym for scapolite, first described from Amatrice, Italy. While the name is no longer valid, it reflects the historical tendency to assign local variants distinct names before mineral classification was standardized.

In short: Amatrice = old name for scapolite, tetragonal feldspathoid, first described in Amatrice, Italy.