Description
Black Tourmaline – Natural Schorl Crystal from Brazil
This genuine Black Tourmaline specimen from Brazil is a substantial natural crystal of the mineral species Schorl, selected for its impressive size, well-defined structure, and collector appeal. Each piece measures approximately 50–80mm, offering a bold and striking display specimen suitable for mineral cabinets, educational collections, or decorative geological displays. The photograph shows an example of the actual specimen you will receive. Please refer to the listing images for full sizing and natural variation within this range.
Your Black Tourmaline crystal includes a Certificate of Authenticity lifetime guarantee generic card, confirming it is a 100% genuine natural mineral specimen.
Mineral Species & Chemical Composition
Black Tourmaline is the common name for Schorl, the iron-rich member of the tourmaline group. Its general chemical formula is:
NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄
It belongs to the cyclosilicate mineral group and crystallises in the trigonal crystal system. Tourmaline is notable for its complex borosilicate chemistry and distinctive elongated crystal habit.
Key mineralogical properties include:
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Mineral Group: Tourmaline (Cyclosilicate)
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Crystal System: Trigonal
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Hardness: 7–7.5 on the Mohs scale
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Lustre: Vitreous to subvitreous
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Transparency: Opaque
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Fracture: Uneven to subconchoidal
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Cleavage: Indistinct
The deep black colour results from high iron content within the crystal lattice.
Crystal Habit & Surface Characteristics
Brazilian Black Tourmaline commonly forms elongated prismatic crystals with strong vertical striations along the length of the prism. In the 50–80mm size range, specimens may display:
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Prominent columnar growth
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Deep linear striations
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Natural termination faces
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Intergrown crystal clusters
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Minor surface irregularities consistent with natural formation
The larger size enhances the visibility of the trigonal symmetry and surface texture, making it an excellent example of classic tourmaline crystal structure. No artificial dyes or enhancements have been applied.
Geological Formation – Brazilian Pegmatites
Brazil is one of the world’s most important sources of high-quality tourmaline specimens. Black Tourmaline typically forms in:
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Granitic pegmatites
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Metamorphic schists
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Hydrothermal vein systems
During the late stages of magma crystallisation, boron-rich fluids allow tourmaline to crystallise within cavities and fractures. Iron-rich conditions favour the formation of Schorl over other coloured tourmaline varieties.
Associated minerals in Brazilian deposits may include quartz, feldspar, mica, garnet, and spodumene. The pegmatitic environment encourages the development of large, well-defined crystals.
Collecting & Display Appeal
Due to its distinctive crystal form and durability, Black Tourmaline is highly sought after by mineral collectors. The 50–80mm size makes this specimen particularly suitable for:
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Statement display pieces
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Mineral cabinet highlights
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Geological education collections
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Collector gift items
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Desk or shelf display
In some traditions, Black Tourmaline is spiritually associated with grounding and protection; these associations are belief-based rather than scientific.
Authenticity & Individual Selection
Each Black Tourmaline specimen is carefully chosen for crystal integrity, structural definition, and natural character. The listing photograph shows an example of the actual specimen you will receive within the stated 50–80mm size range. Please review all images for scale and natural variation.
Every piece includes a Certificate of Authenticity lifetime guarantee generic card, confirming its genuine natural origin from Brazil.
A classic example of iron-rich tourmaline formed in boron-bearing pegmatitic environments, this Brazilian Black Tourmaline specimen offers geological significance, impressive scale, and strong collector appeal as a display-quality mineral crystal.





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