Matulaite Locality: Bachman Mine, Hellertown , Lower Saucon Township, Northampton County, Pennsylvania , USA ( Locality at mindat.org ) Size: 4.3 x 1.7 x 1.6 cm. Matulaite is a rare phosphate that is only found in a handful of worldwide localities. Pieces from the type locality at the Bachman mine are U.S. classics. This specimen features a covering of white Matulaite on one side of Limonite matrix. This particular specimen came directly from Marge and Vincent Matula (the species was named after Marge) and was a gift from Will Shulman to Pat Gross in April 1984. Rich Kosnar acquired the Pat Gross collection in the early 1990s, as she was a dear friend to Rich during his youth and early years of mineral dealing. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Matulaite
Matulaite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Fe³⁺Al₇(PO₄)₄(PO₃OH)₂(OH)₈(H₂O)₈·8H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/n).
Key properties: Mohs hardness 1.5; specific gravity 2.27; White streak; Vitreous luster; optically biaxial.
IMA symbol Mat, IMA status: approved, named in 1977.
Occurs as an uncommon secondary mineral in the oxidized zone of phosphatic iron deposits.
It is found associated with Beraunite, rockbridgeite, dufrénite, cacoxenite, strengite, wavellite, goethite, hematite, afmite.
The mineral was named to honor Margaret Mary Matula (b. 1925), Allentown, Pennsylvania, USA, who supplied some of the first specimens.