Francis M. Hueber

And a Baveno twin from Baveno

Specimen 105 mm wide, prominent crystal 30 mm high.

The specimen above is a classic example of orthoclase feldspar twinned according to the Baveno law, in which the contact between the two crystal elements is the {021} plane. It’s cooler because it’s from Baveno, northwest of Milan in northern Italy where such twins are so common they gave their name to the law.

But I mostly want to write about the previous ownership of the specimen, which I recently acquired from Paul Senn.

Francis M. Hueber, photo from his obituary. I don’t know who to credit it to.

The piece is from the collection of Francis M. Hueber, one of the most prominent paleobotanists of the late 20^th century. Born in Oklahoma in 1929, his college education was at Butler University in Indianapolis, Indiana, and Cornell in Ithaca, New York. He was the first paleobotanist hired by the Smithsonian’s National Museum of Natural History, in 1962, and he stayed there until he retired in 2001. He died in 2019.

Prototaxites as reconstructed by Canadian geologist John William Dawson in 1888.

Hueber’s professional focus on early plants led to seminal work on the enigmatic Devonian organism Prototaxites, which grew to a length or height of more than eight meters (26 feet), making it the largest land life of its time (Devonian, about 380 million years ago). Hueber first recognized it as a fungus, and despite serious initial skepticism, he was eventually vindicated in his interpretation.

He started collecting minerals as a teenager and pursued the hobby for 75 years. Parts of his massive, excellent collection were displayed at the Mineralogical Museum of the University of Delaware.

I don’t have many specimens that belonged to prominent collectors, so this one is rather special to me, on a par with the USGS Monograph I have that once was owned by Florence Bascom, the first female geologist hired by the USGS and the founder of the geology department at Bryn Mawr College (that story is reported in my compilation of posts on the History of Geology, PDF linked here).

Hueber’s full biography is available here.

The 30-mm orthoclase crystal in the rock at the top of this post is associated with green epidote and micas including muscovite and probably “zinnwaldite,” the informal name for a series between the micas siderophyllite (potassium-iron aluminosilicate) and polylithionite (potassium-lithium aluminosilicate). The dark coating on one face of the prominent orthoclase crystal is a mix of epidote and hematite.

The minerals probably grew in miarolitic cavities and pegmatitic phases in pink granite intruded during the latter part of the Variscan Orogeny about 280 million years ago (Dino and others, 2020, Towards Sustainable Mining: Exploiting Raw Materials from Extractive Waste Facilities: Sustainability 12:2383).

The granite at Baveno has been quarried since the 1500s for use in columns for the Cathedral of Milan and numerous other structures around the world.

View toward the Baveno quarries and Mont’Orfano, painting by Gilberto Borromeo Arese (1815-1885).