Rosebud Mine Miargyrite, etc.

Miargyrite on Drusey Quartz

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

3.4 X 2.4 X 1.8 cm

A final piece for the Gallery, featuring a 0.9-cm wide mass of crystalline Miargyrite with sections of earlier blades of Pyrrhotite. A large section of the mass is contacted where it likely grew against the opposite vein wall before separation.

Regardless, the crystallized portions of the Miargyrite cluster reach several millimeters, and their isolation on the drusey Quartz on greenish white matrix is a unique presentation in the mineral world.

                                                         #RSBD-012       $65

2011 view looking south at the realized Rosebud Mine. Note: without a small marker, you wouldn't know this used to be a mining operation, as even the original drainage patterns and outcrops were reconstructed using aerial photos. 

Miargyrite with Pyrrhotite and Celadonite

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

2.7 X 2.3 X 1.9 cm

A 1.9-cm-long string of crystals of Miargyrite to 5-mm, with associated brassy Pyrrhotite crystals, runs the surface of a thin druze of Quartz on bluish green Celadonite and a minor coating of a reddish brown-colored mineral.

The Miargyrites on this specimen are more notably blackish silver than others in this Gallery, and the matrix is more robust. I added this because it is the only piece in this offering that is from the collection of late mineral dealer Harvey Gordon, and a different part of the mine than the others. Despite appearances, the Miargyrites on the face of the specimen are complete! The "rough" parts are actually areas of smaller clusters of minute Miargyrite crystals.

The price on this on is also relatively inexpensive, as I obtained this one from Harvey's collection for a relatively small price as part of a very large overall deal for lots of pieces!

                                                      #RSBD-008       $135

12 Specimens added August 22, 2017

Miargyrite on Pyrrhotite

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

1.6 X 1.1 X 0.7 cm

Crowned by a perfect 5-mm wide, compressed crystal, this is my favorite of the pieces in this listing, and is the best Miargyrite-Pyrrhotite combo I've seen.

Minor contacts on the edges are easily visible in the photos on the bottom-left part of the specimen in the photo to the left, but comprise less than 10% of the actual surface area of the piece.​​

                                                     #RSBD-001       $650

Miargyrite

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

1.0 X 0.7 X 0.6 cm

The largest single crystal in the collection, this complex form exhibits variable luster, ranging from lustrous silver faces to a few highly lustrous, slightly purplish silver faces. There is a 2.5-mm-long chip obvious on the lower left in the photo on the left, and very minor "rubbing" on the top edge; the remainder of the display is complete and impressive for its size and quality.

                                                        #RSBD-007       $425

Miargyrite

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

2.0 X 1.6 X 1.0 cm

A pile of complete, lustrous Miargyrite climbs a couple thin blades of Pyrrhotite (visible on the back). The result is an aerial cluster of sparkling, perfectly terminated Miargyrite crystals perched on a mint-green to pale pink-white, completely Clay-altered matrix. A thin layer of drusey Silica helps to anchor the piece, both physically and aesthetically.

                                               #RSBD-005       $400

Miargyrite on Drusey Quartz

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

4.9 X 3.3 X 2.0 cm

An fine miniature-sized specimen, featuring clusters of sharp and lustrous Miargyrite to 5-mm across, with some individual crystals reaching 2 mm in length. These clusters are scattered across a relatively broad face of slightly translucent drusey Quartz that mostly covers a mint-green core of clay-altered volcanic host rock.

Thankfully, and in spite of the apparent cracks shown in the photos, there are multiple additional veinlets of Quartz that make this a robust specimen. 

                                                         #RSBD-010       $85

Miargyrite on Pyrrhotite

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

2.5 X 2.4 X 2.0 cm

Another pile of complete, lustrous Miargyrite climbs a couple thin blades of Pyrrhotite, visible in the photos. The result is an aerial cluster of sparkling, perfectly terminated Miargyrite crystals perched on deep brassy discs of Pyrrhotite, standing above a mint-green to pale pink-white, completely Clay-altered matrix.

A thin layer of drusey Silica helps to anchor the piece physically. Otherwise, the Clay matrix would likely have "dissolved" at some point, as with the vast majority of specimens I've seen from here.


                                               #RSBD-006       $300

Miargyrite with Pyrostilpnite

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

3.0 X 2.8 X 1.4 cm

Scattered clusters of small Miargyrite crystals to 5-mm across, with individual crystals reaching lengths of better than 2 mm, adorn a mint-green matrix completely stabilized by a micro-druse of crystalline Quartz.

At the upper left of the upper cluster of Miargyrite in the photo to the left is a very small, 1-mm-long, cherry-red Pyrostilpnite.

I've not valued the presence of the Pyrostilpnite into this specimen, as I can't quite capture it in an adequate image.

                                                            #RSBD-009       $80

Miargyrite with Pyrostilpnite

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

1.6 X 1.5 X 0.6 cm

Under any magnification, the quality of this crystalline mass is clear; these are undamaged, very well articulated crystals, with at least one sub-2-mm crystal of Pyrostilpnite nestled in the mix.

Pyrostilpnite is a polymorph of Pyrargyrite.

Despite it's presence, I've not valued the Pyrostilpnite association into this piece, as it's already one of the top 1% in terms of Miargyrite specimens I've seen in the last 20 years.

                                       #RSBD-002       $500

The reclaimed Rosebud Mine is located in the Kamma Mountains, Pershing County, Nevada, USA. Between 1997 and 2000, it produced approximately 385,000 ounces of Gold and 1,250,000 ounces of Silver from structurally and stratigraphically controlled high-grade veins in Clay-altered volcanics.

​I toured the active mine in the late 1990s, and was part of the last due-diligence team to assess any additional mining potential in the early 2010s. Long story short, there is no plausible scenario to mine any of the existing mineralization, and the area has seen no work since circa 2013.

​These specimens are from the only serious professional recovery effort, made by another mineral dealer who had a contract with the mine, but only had one chance to collect before the mine shut down. A very few larger pieces were sold earlier, but I bought essentially the entirety of the lot more than a decade ago, and started bringing out a few at Tucson and the Spring Denver Show this year.

Miargyrite on Drusey Quartz

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

4.9 X 3.3 X 2.0 cm

Miniature-sized specimen with a prominent, perfectly positioned, 7 X 5 X 4 mm cluster of lustrous Miargyrite crystals that individually range to 0.7 cm in length. The Miargyrites show a slight purplish silver tone, indicative of other "ruby-silvers," such as Pyrargyrite. Add a stunning contrast with the light-greenish white matrix and a thicker than normal layer of stabilizing drusey Quartz, and call this one of the single best specimens from the collection. Even the backside of the upper crystal cluster is complete, with local areas of on a micro-crystals associated with earlier Pyrrhotite.

                                                                            #RSBD-011       $375

Miargyrite

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

1.5 X 1.1 X 0.8 cm

The best cluster of Miargyrite from the group, this cluster features a prominent, slightly hoppered crystal measuring a relatively whopping 8 X 5 mm!

I use the term  "relativey whopping" with full respect for this extremely rare Silver-bearing species, as it seldom pushes the 1.0-cm threshold...

Note: there is a small contact on the front-face, as shown by a minor color-irregularity in the photo to the right, showing a fresh exposure of the purplish silver interior this rare "Ruby Silver."

                                     #RSBD-004       $675

Miargyrite

Rosebud Mine, Rosebud District, Pershing County, Nevada, USA

1.2 X 1.2 X 1.0 cm

An undamaged stack of Miargyrite crystals to 2 mm adorn a thin bit of silica coating a chip of mint-green, clay altered matrix.

Small, but very good representation of this difficult to find material...

                                                      #RSBD-003       $175

A number of other pieces, primarily Barite, Pyrrhotite, and/or Stibnite, were sold to the late Harvey Gordon by miners. In 2006, I also bought every decent piece he still owned. For this update, though, I'm going to stick with the Miargyrite specimens, as they are some of the best in the world, and will add additional specimens later. I am going to post my best specimens first, and will work to add less expensive representations of the various styles and associations at some point in the future.

Note: the matrix for all the specimens is nearly 100% clay-altered volcanic rocks, is commonly very soft, and generally falls apart easily. As a result, most of the best Miargyrite specimens are thumbnail-sized crystal masses. With a few notable exceptions, including the specimen in the Spann Collection, and the one photographed in the Minerals of Nevada book, most of the matrix Miargyrites are small clusters on a greenish-white matrix, with a sparkling micro-druse of quartz on a mint-green mixture of Celadonite on earlier, creamy-white, clay-altered matrix.