Alleghanyite (xls); Bald Knob, Alleghany Co., AR, USA; Min; unique piece.

$42.95
Only 1 left
Item number
A1025403

Embedded Alleghanyite crystals (Top!) from Bald Knob, Alleghany Co., AR, USA– miniature specimen as unique piece

 

This miniature specimen features a fine-grained, tightly embedded formation of Alleghanyite in dark matrix with striking reddish-brown and pink color zones. The texture shows narrow, undulating bands that give the piece a dynamic, almost layered appearance. The vivid color and natural contrast make this a particularly attractive specimen.

Alleghanyite is a rare manganese silicate of the humite group, typically found in Mn-rich metamorphic rocks. It crystallizes under medium pressure and high temperature conditions and is among the lesser-known representatives of manganese silicates. Aesthetically appealing specimens like this are uncommon.

Geology & Origin:

Bald Knob in Arkansas is considered a classic locality for manganese-rich metamorphic rocks in the USA. The region is characterized by schists and metasediments with high manganese content, which under metamorphic conditions give rise to numerous scientifically interesting silicates. Alleghanyite from this locality is prized by collectors for its rarity and distinctive coloration.

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

More Information
shipment-weight, NOT netto weight (kg) 0.080000

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