Dumortierite; Minas Gerais, Brazil; Scab; unique piece
Dumortierite from Minas Gerais, Brazil – small cabinet specimen as unique piece
This small cabinet specimen shows Dumortierite from Minas Gerais, Brazil. The piece is characterized by its typical blue and white coloration and the distinctive structure of this silicate mineral.
The Dumortierite crystals occur as fine fibrous to densely intergrown aggregates within the matrix, creating the characteristic blue slightly wavy banding in the rock. Individual crystals are not clearly separated but merge into a compact finely structured mass. Nevertheless, the crystals provide a clearly visible texture and give the specimen its typical decorative appearance.
Geology & Origin
Dumortierite is an aluminium borosilicate that forms mainly in metamorphic rocks. It develops under high pressure and temperature conditions, often in quartz rich rocks such as gneisses or quartzites.
Minas Gerais in Brazil is one of the world’s most important localities for Dumortierite. The region is well known for its wide variety of minerals and for particularly colorful and aesthetically appealing specimens.
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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