New The Americas Update 17 September 2021

17 September 2021

OUR updates this week jump continents; we toured Africa on Tuesday and today it’s the turn of the Americas, covering both North and South, going the whole hog you might just say!

With two such vast and mineralogically-rich continents to choose from, it will come as no surprise the selection of 21 specimens is wide and varied. These include lots of aesthetics and a smattering of the more unusual. There are lots to highlight, so let’s get going…

Mauve Vesuvianite from Jeffrey mine in Québec, Canada, is a perennial favourite because the colour is so outstanding. We have a beautiful miniature with densely intergrown Vesuvianite crystals to 1.5 cm on a slightly green tinted Diopside matrix. The beautiful and lustrous rich purple-mauve crystals stack-up to form an interwoven cluster.

From the 1991 Christmas Pocket discovery at the Crystalline mine in Tuolumne County, California, look at this excellent compact sheet of Native Gold, approximately 4.5 cm high and tapering from 3 to 2.5 cm wide from bottom to top. The sheet’s somewhat botryoidal surface shows occasional crystallized patches and with a net weight of 24 grams, the specimen has a very ‘solid’ look and feel to it, despite being sheet Gold! And while in the domain of native metals, examine the glass phial containing alluvial rounded grains of metallic silvery Native Platinum to approximately 1 mm from the Pinto River in the San Juan Basin of Colombia. When seen in a collection, Platinum always contributes that special feel of the rare and exotic!

From Ballard mine at Baxter Springs in the Tri-State District of Kansas, lead grey cubic crystals of metallic Galena to 2.2 cm display interesting surface growth patterns and scattered over the triangular olive-green matrix are beautiful gemmy orange-red micro-crystals of ruby Sphalerite of between 1 and 3 mm.

One specimen we simply have to mention is an incredibly unusual pseudomorph from the Payún volcano in the Malargüe Department of Mendoza, Argentina. This volcano is renowned for these remarkable pseudomorphs which are very distinct and probably unique to this locality; formed in the volcanic fumaroles. Collecting is now totally forbidden, although it does sound like a rather dodgy and dangerous place to visit! Three intergrown octahedral Hematite crystals sit on an elongated hopper crystal measuring just over 4 cm long. The Hematite forms pseudomorphs after the Martite variety of Magnetite. The entire specimen is a mixture of glistening black Hematite micro-crystals against a background and framework of earthy-brick red Hematite. It is truly fantastic!

Chuquicamata mine in Chile is the world's largest open-pit copper mine and exploits a porphyry copper deposit. From here we have a rare example of the hydrated sodium-copper sulphate, Kröhnkite. Forming a rich sky to sapphire blue vein, the Kröhnkite has formed on both sides of a thin veinlet of Goethite. It is a lovely large miniature and from its type locality.

Turning to some silvery-grey species, these can often appear dull and uninteresting, but these four certainly buck the trend, each being a little beauty! In alphabetical order we’ll look at a Bournonite, a Columbite, a Cylindrite and a Tetrahedrite. The fine cog wheel Bournonite crystal is associated with sooty black micro-tetrahedral Freibergite and Pyrite on Quartz from the Viboras mine at Machacamarca in Bolivia. From Minas Gerais in Brazil, this magnificent 5.7 cm tall tabular crystal of Columbite, an ore of niobium, is certainly worthy of a look. The crystal is largely fully intact with well-defined black prism faces and a metallic, slightly waxy lustre. It is a stunning example of this relatively rare species. I always like Cylindrite, the lead-tin-iron-antimony sulphosalt, this fine miniature originating from the Santa Cruz mine in the Oruro Department of Bolivia. The cylindrical crystals measure up to 3.5 cm by 1 to 2 mm in diameter and form concentric shells of overgrown cylindrical layers. This specimen comes with a Dr F. Krantz stock label and is ex. the Josef Clemente Collection of southern Germany. And our final in this group is the Tetrahedrite from Casapalca in the Huarochiri Province of Peru, and what a Tetrahedrite it is! Sharp intergrown isometric crystals are developed as steep sided pyramids to 3.5 cm with heavily striated prism faces, parallel to one edge. The metallic black crystals are so reflective they appear silvery-blue in strong light. A superb miniature which elevates Tetrahedrite to a new level of aesthetic appeal!

Although we never cover every specimen in this review, there remain a few which have to merit a quick mention. A Rhodochrosite with Quartz for example, from Pasto Bueno in Ancash Department, Peru. Three sharp, rhombic Rhodochrosite crystals nestle amongst an array of near-vertical colourless prismatic Quartz crystals. The Rhodochrosite crystals are a beautiful translucent-gemmy vibrant pink measuring overall to 1.5 cm while the lower halves of the Quartz crystals are coated in white Muscovite mica with an attractive pearly lustre. In the gem department, a single gemmy to translucent Aquamarine Beryl, 5.9 cm long, displays well-defined growth zones and pinacoid terminations at either end. This is from Teófilo Otoni in the Mucuri Valley of Minas Gerais, Brazil.

Let’s end with a Zircon, a lovely miniature example from the Tigerville Prospect in Greenville County, South Carolina. A fine octahedral Zircon crystal with edges to 1.6 cm embedded in an apricot speckled, creamy Feldspar matrix. The Zircon is opaque creamy cherry-pink and displays three entire faces of the upper four-sided pyramid.

Two mineral-rich continents so, hopefully, an interesting and varied collection from which to select and be suitably tempted. From well crystallized ore minerals to the more gemmy end of the mineralogical spectrum, relax over the weekend and take time to look in more detail through the Crystal Classics’ website via the links for each specimen. We hope you find exactly what you’re looking for, so adding another special specimen to your collection. PT

Here is what you have to look forward to in next week's update:

Tuesday 21st September & Friday 24th September - British

                                         

If you'd like to see a video of any of the specimens listed above then please contact us at orders@crystalclassics.co.uk and we'll be happy to assist you. We endeavour to respond to all enquires within 24 hours during weekdays, however at the weekend it might take us a little longer to respond.

 

DATES FOR YOUR DIARY

Crystal Classics, and our sister company UK Mining Ventures, will be in attendance at the following shows for the remainder of 2021:

SEPTEMBER 10-18
Colorado Mineral and Fossil Fall Show 2021
Crowne Plaza Denver Airport Convention Center 15500 E 40th Ave, Denver, CO 80239, USA

SEPTEMBER 16-19
Hardrock Summit 2021 - Evolution
Colorado Convention Center, Four Seasons Ballroom 700 14th St, Denver, CO 80202, USA

OCTOBER 9-10
The Bakewell Rock Exchange 2021
Lady Manners School, Bakewell, Derbyshire DE45 1JA, UK

OCTOBER 22-24
The Munich Show 2021
Exhibition Center Messe München, WEST Entrance, Munich, Germany

NOVEMBER 20
The Sussex Mineral & Fossil Show 2021
Haywards Heath College, Harlands Road, Haywards Heath, West Sussex RH16 1LT, UK

NOVEMBER 27
Crystal Classics Winter Open Day 2021
No.1, The Old Coach Yard, East Coker, Somerset BA22 9HY, UK

 

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MINERAL WISH LIST

We also offer an additional service that enables you, as our customer, to contact us via orders@crystalclassics.co.uk with your mineral wish list to enhance your current collection, but are unable to find the right specimens on our website. We have 1000's of specimens in our general stock that do not appear online.

Author: JH
Categories: Updates

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