Szaibelyite is a hydroxy magnesium borate, MgBO2(OH). It is found in marbles, skarns and serpentinites, and may be fibrous (like this sample) or powdery. This s — Photo: Shannon Heinle · CC0
Szaibélyite
Szaibélyite is an IMA-recognized mineral species in the borate class, with the chemical formula MgBO₂(OH).
It crystallizes in the monoclinic crystal system (space group P2_1/a).
Key properties: Mohs hardness 3.5–4; specific gravity 2.62; typically white or colorless or yellow; White streak; Silky to dull luster; optically biaxial.
IMA symbol Sza, grandfathered status — known before the IMA’s founding, named in 1862.
Uncommon in marine evaporite deposits; in boron-bearing contact metasomatized dolomitic marbles and skarns, and metamorphosed banded iron formation.
It is found associated with Ludwigite, hulsite, magnetite, fluoborite, vonsenite, sinhalite, nordenskiöldine, warwickite, brucite, aragonite, brugnatellite, clinohumite.
The mineral was named to honor István Ádám Rudolf Szaibély (1777–1855), Rézbánya, Hungary [now Băiţa, Romania], mine surveyor, who collected the first specimens.
Collections: Collector Favorites, Rare & Remarkable.