Brugnatellite
Brugnatellite is a carbonate mineral recognized among collectors for its crystal form and distribution, with several world-class Chinese localities.
About Brugnatellite
Brugnatellite belongs to the carbonate class and has the chemical formula Mg6Fe3+(CO3)(OH)13·4H2O. It crystallizes in the trigonal system and is relatively soft, requiring careful handling. Its combination of structural character and global distribution make it a recognized species in both systematic and aesthetic collections.
Identification & care
Crystals commonly develop as tabular hexagonal platelets; foliated. Its color is typically pale yellow to pale brown. The luster is waxy to pearly, the streak is white to pale yellow, and specimens are typically translucent. The cleavage is perfect {0001}. The fracture is uneven, which aids identification.
Collector context
How it forms
Brugnatellite forms in serpentinite and altered ultramafic rocks. It is commonly found in association with pyroaurite, hydrotalcite, antigorite, magnetite.
Classic Chinese localities
Huanggang Fe-Sn deposit is an important Chinese source for the species.
Why collectors care
Collectors pursue Brugnatellite for the clarity of its crystal form and, in good material, saturated color that reads instantly across a display case. A well-terminated brugnatellite on clean matrix photographs well, identifies quickly, and anchors a cabinet piece. Top Chinese specimens over the last two decades have reset the bar for what brugnatellite looks like at collector grade.
What affects value
Value in Brugnatellite is assessed, in typical order of weight, against: (1) locality provenance; (2) size relative to the species norm; (3) crystal form and termination sharpness; (4) color saturation and zoning; (5) transparency and internal clarity; (6) matrix quality and aesthetic balance; (7) condition (absence of damage, chips, or repair). Cleaning quality and verified locality documentation act as multipliers across the above.
Naming history
The name Brugnatellite has a specific etymological and historical context — see Mindat's reference entry for provenance details. We have retained naming data at the record level; published prose is paraphrased from factual fields rather than copied from source.
Frequently asked questions
What is Brugnatellite?
Brugnatellite is a carbonate mineral recognized among collectors for its crystal form and distribution, with several world-class Chinese localities.
What is the chemical formula of Brugnatellite?
The chemical formula of Brugnatellite is Mg6Fe3+(CO3)(OH)13·4H2O.
What crystal system does Brugnatellite belong to?
Brugnatellite crystallises in the Trigonal crystal system.
References & databases
Mindat.org is the world’s largest open mineralogy database. Our descriptions are written independently and fact-checked.