Cornwallite crystals from St. Day, Cornwall, UK – miniature specimen as unique piece
This small cabinet specimen shows Cornwallite crystals from St. Day, Cornwall, UK. The piece is impressive due to its dense coverage of intensely green crystals evenly distributed across the light granular matrix, creating a very lively overall appearance.
The Cornwallite crystals are clearly visible and occur as numerous small densely packed crystal points. They form a fine crystalline sparkling surface with a fresh strong green color typical of this arsenic bearing copper mineral.
Geology & Origin
Cornwallite is a rare copper arsenate that forms in the oxidation zone of copper deposits. It develops through the weathering of arsenic bearing primary minerals and commonly occurs as fine crystalline coatings or aggregates.
Cornwall, especially the St. Day area, is a classic European locality for secondary copper minerals. The historic mining districts there are well known for their great mineralogical diversity and numerous rare species.
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
