Pharmacosiderite xls; St. Day, Cornwall, UK; Gerd Tremmel collection; Scab; unique piece
Pharmacosiderite crystals from St. Day, Cornwall, UK Gerd Tremmel collection – small cabinet specimen as unique piece
This small cabinet specimen shows Pharmacosiderite crystals from St. Day, Cornwall, UK, from the Gerd Tremmel collection. Numerous finely developed Pharmacosiderite crystals occur on the dark iron rich matrix, displaying an olive green to brownish green color. The crystals are clearly developed and form drusy coatings as well as small densely packed crystal groups in cavities and on irregular fracture surfaces. The vitreous luster of the crystals contrasts effectively with the rough matrix, giving the specimen a lively and richly detailed surface with well visible crystal structure.
Geology & Origin
Pharmacosiderite is a hydrated iron arsenate that forms secondarily in the oxidation zone of arsenic bearing ore deposits. It develops through the alteration of primary arsenic minerals under the influence of oxidizing solutions. The St. Day area in Cornwall is historically known for its complex tin and copper deposits with diverse secondary mineral formation. The crystals shown here illustrate typical formation processes in fractures and cavities of oxidized ore zones.
This table is for general information and orientation, although the sizes of the stones may vary. In addition, this specification is handled differently from region to region.
| Sizes | Description | approx. Sizes in mm/cm | approx. Sizes in INCH | |
| Capsule | Capsule | 0.1–0.5 mm in a transparent hard capsule (approx. 1 cm) | capsule contents 0.1–0.5 mm | capsule contents 0.004–0.02 in |
| TN/mm | Micromount (TN = Thumbnail) | everything fitting in a TN Perky box or a MM box of approx. 1 in | approx. 0.5–2.5 cm | max. 1 in |
| Min | Miniature specimen | will not fit a TN or MM box anymore | approx. 2.5–5 cm | approx. 0.2–1.0 in |
| Scab | small cabinet specimen | approx. one-third to half a hand size | approx. 5–9 cm | approx. 1.0–2.0 in |
| Cab | cabinet specimen | full hand size | approx. 9–15 cm | approx. 2.0–3.5 in |
| large Cab | large cabinet specimen | approx. two hand sizes | approx. 15–30 cm | approx. 3.5–6.0 in |
| very large Cab | very large cabinet specimen | everything larger, no upper limit |
Abbreviations commonly used in mineralogy.
| Abbreviation | Meaning |
| xl | single crystal, possible with matrix |
| xls | noticeable crystals |
| (xl) | embedded or damaged |
| (xls) | embedded or damaged |
| MASS | massive and/or amorphous pieces |
| TYP | type locality of the original description |
| SWUV | shortwave-UV-reaction |
| UV | ultraviolet reaction |
| SC | self-collected |
| U | unique (single unique piece) |
Usage Instructions
This product is ideal as a collector's item, decorative element, teaching material, or for scientific and exhibition purposes.
Legal Notices
Safety
We accept no liability for damages resulting from improper and/or non-recommended use. Please carefully assess the suitability of the product before any alternative use.
Responsible Provider
Mikon Mineralienkontor GmbH
Steinslieth 11
D-37130 Gleichen OT Klein Lengden
Email: info@mikon-online.com
| shipment-weight, NOT netto weight (kg) | 0.100000 |
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