Szaibelyite

specimen number:
2133337

location:
Bolinas Bay, Marin Co., California, USA

description:
White crystalline szaibelyite quite rich throughout matrix. The specimen comes with an old label from noted collector W. Scott Lewis of Hollywood, California.

Szaibelyite is a relatively uncommon magnesium borate mineral that forms almost exclusively as a secondary alteration product within magnesium-rich skarns and metamorphic borate deposits. Geologically, it develops through the hydrothermal alteration of primary borate minerals, such as suanite, or via the reaction of boron-bearing fluids with surrounding dolomite and serpentine rocks under low-to-moderate temperature conditions. The mineral typically crystallizes in the monoclinic system but rarely forms distinct, individual crystals; instead, it is most frequently found as chalky, compact masses, nodular aggregates, or dense, intergrown networks of fine, flexible, hair-like fibers. Szaibelyite generally ranges in color from pure white to pale shades of yellow or gray, and it possesses a relatively low Mohs hardness of 3.0 to 3.5.

W. Scott Lewis was a prominent American mineral collector, amateur astronomer, and commercial specimen dealer based in Hollywood, California, who was highly active during the early-to-mid 20th century. Operating as a dedicated purveyor of geological materials, he established a widespread mail-order business that supplied mineral collectors, schools, and researchers across the country with affordable, well-documented mineral, rock, and fossil specimens. Beyond his commercial work, Lewis was deeply committed to promoting earth science education and hobbyist community engagement, serving as a key early member and frequent lecturer for regional organizations like the Mineralogical Society of Southern California. For decades, he authored and self-published specialized educational circulars, newsletters, and catalogs from his Hollywood address, providing accessible mineralogical insights and field collecting guides that helped popularize amateur mineralogy throughout the western United States.

Questions about this specimen?
Send an email or call us: 314-341-1811.