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10 specimens listed
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SOLD Milarite, Quartz and Valencianite
stock #SOLD A7-382-(463)
Valenciana Mine (Mina La Valenciana), Municipio de Guanajuato
Guanajuato, Mexico
8.2 x 6 x 2 CM (cabinet)
price: $0
Late Summer 2021

Several bright yellow Milarite crystals are scattered on a well-crystalized matrix of milky Quartz and sharp Valencianite crystals. This is from the find made decades ago at the Valenciana Mine and this specimen is quite rich, this specimen has more than a dozen crystals reaching up to 5 mm. The Valencianite (a type of Adularia as this is an Orthoclase) is especially sharp and partly transparent. This is complemented with the Quartz crystals which are mixed in and give a nice extra bit of luster.

Pyrargyrite (Ruby Silver crystals)
stock #AX-29-047
San Juan de Rayas Mine, Municipio de Guanajuato
Guanajuato, Mexico
2.8 x 2.7 x 2 CM (thumbnail)
price: $380
new year 2021

Super lustrous, metallic crystals of Pyrargyrite in a cluster with no matrix. Many of the larger crystals are distinctly twinned. These look silvery-black without very strong lighting but a few edges show the bright red flash and glint of the "ruby" color. The crystals are opaque for the most part but a few edges show some translucence. A mid 1980 vintage Silver secondary specie from the famed and prolific San Juan de Reyes Mine (Guanajuato, Mexico). A hefty thumbnail in good condition, there is some roughness and the backside is the point of removal but this is still in better shape than usual for this delicate mineral. The Ruby Silvers of Mexico are now considered classics and are quite different than the old European specimens. Choice.

stock #AX-22-175
San Juan de Rayas Mine - Level 407
Guanajuato, Mexico
2.2 x 1.3 x .6 CM (thumbnail)
price: $140
new year 2021

Branching crystals of Acanthite forming a tree-like thumbnail with very bright metallic luster. Complete all around, undamaged and pretty. A very good yet still affordable Silver specie from the famed Guanajuato deposit. This area has been continuously mined for Silver since the discovery in 1585, and this was the world's largest producer for many years. Amazingly there are still a few operating mines and Silver minerals are still found though far less than before.

Milarite on Valencianite and Quartz
stock #AX-10-589
Valenciana Mine (Mina La Valenciana), Municipio de Guanajuato
Guanajuato, Mexico
7.8 x 5.8 x 5.4 CM (cabinet)
price: $160

One of the more uncommon Beryllium Silicate species, Milarite is a real "mineral collectors" specie. This piece is from the find some decades ago in Guanajuato, Mexico. The Matrix is a mix of Quartz and Valencianite (variety of Adularia). The Valencia Mine is the type locality for the Feldspar and was the source of these small bright yellow Milarites which were big news in the mineral world. This piece has several very small crystal and one a bit larger (about 8mm). These are flat habit and the structure is not as evident without good magnification. A fair example of the find that is not crazy expensive.

Polybasite on Acanthite
stock #20.1-112
Guanajuato, Municipio de Guanajuato
Guanajuato, Mexico
3.2 x 2.4 x 1.7 CM (thumbnail)
price: $3200

A killer specimen with exceptional form, the main crystal being textbook perfect, sharp and perfectly defined. Formerly in the collections of Carl Acosta and Brett Keller, this is just barely within the size limit to be classified a thumbnail. The Acanthite matrix is the "melted" look type and is a fine contrast to the large Polybasite. Displays well from either side, what we consider to be the front or best view has a nice metallic patina. Most of the Polybasite we have seen from Guanajuato is more crude or has overgrowths of Pyrite, this is just a superb example of the specie and extraordinary for the locality.

Pyrargyrite with Polybasite, Chalcopyrite, Quartz
stock #20.1-138
San Juan de Rayas Mine, Municipio de Guanajuato
Guanajuato, Mexico
6.1 x 3.8 x 3.4 CM (cabinet)
price: $650
Spring 2020

Ruby Silver crystals (Polybasite) are nicely grouped on the Quartz matrix. Several small Polybasite crystals with classic hexagonal form are present as well, these covered by druzy Chalcopyrite. Esthetic, lustrous and in excellent condition with no visible damage. With strong lighting the translucent ruby color is revealed but under normal display these look like metallic black crystals. Very clean, the polybasite shows well formed independent crystals even though there are clustered in groups.

Apophyllite - pink
stock #16.1-1266
Guanajuato, Municipio de Guanajuato
Guanajuato, Mexico
8.7 x 6.8 x 4.6 CM (cabinet)
price: $260

A fine crust of Apophyllite crystals with a light pink color and glassy luster. An older piece from Guanajuato with the typical Quartz matrix having amethyst zoning. From the Stanek collection (Brno, Czech republic) we do not see many Guanajuato specimens available, most Mexican pinks are from Zacatecas or Charcas but these were found long before those later finds. In super fine condition.

Acanthite and Polybasite on Quartz
stock #18.1-190
San Juan de Rayas Mine, Municipio de Guanajuato
Guanajuato, Mexico
5.7 x 4.4 x 2.3 CM (cabinet)
price: $440
Spring update

A melted look sculpture of Acanthite crystals on Quartz also holds a few small Polybasite crystals in sharp hexagons. Choice older piece from the San Juan de Reyas mine in Guanajuato. In excellent condition as seen and with a nice dark metallic patina. Under 20 X magnification I can see glints of blood red color that indicates at least a tiny bit of Ruby Silver (Pyrargryite) is also present but very small.