Rough Black Tourmaline (Schorl) cabochons: the top surface retains the crystal's natural striated prismatic texture, unpolished. The back is flat for easy setting.
Item details
| Mineral |
Black Tourmaline (Schorl; cyclic sodium iron aluminum borosilicate) |
| Dimensions |
Approx. 20–40 mm long depending on variant (tolerance ±0.5 mm; shape and size vary per piece, see photo) |
| Shape and back |
Freeform, flat back; rough unpolished top surface |
| Finish |
Unpolished — natural surface with prismatic striations characteristic of Schorl |
| Hardness |
7–7.5 Mohs — we recommend bezel setting; the rough surface facilitates metal grip |
| Origin |
Material acquired from a wholesale lapidary market |
| Treatment |
Untreated |
| Item type |
Unique piece: each cabochon is a singular section of the original crystal |
This specific piece
Rough Black Tourmaline displays its characteristic longitudinally striated surface, a product of the trigonal symmetry of its crystal system.
The flat back is prepared for seating in the bezel, and the natural roughness of the top surface allows the setting metal to grip with more friction than on a polished surface.
How Black Tourmaline forms
Schorl (NaFe²⁺₃Al₆Si₆O₁₈(BO₃)₃(OH)₄) crystallizes in the trigonal system during the consolidation of pegmatitic rocks and in contact metamorphic zones.
What setting it works for
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Open or closed bezel in 925 silver or oxidized brass — the rough texture of the top surface, combined with a dark or oxidized metal bezel, creates a geological contrast that enhances the aesthetic of the piece. The closed bezel protects the crystal edges.
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Statement rings and large format pendants — rough Schorl is a common material in artisan jewelry and signature pieces; its raw appearance fits aesthetics that value the materiality of the mineral over a conventional finish.
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Wire wrap with thick silver or copper wire — an alternative for those working with wire; wire anchored in the rough texture of the crystal provides greater mechanical security than on a polished surface.
Black Tourmaline in lapidary tradition
Black Tourmaline has been present in lapidary cultures since classical antiquity; the Greeks called it "lyngourion" and the Romans used it as engraving material due to its hardness and conchoidal fracture capacity.
The symbolic properties attributed to minerals belong to cultural and historical traditions. They are shared for educational purposes, not as medical advice or a substitute for professional care.
How to recognize genuine Black Tourmaline
Authentic Schorl exhibits longitudinal striations parallel to the crystal's long axis, visible without magnification on the natural surface.
Frequently asked questions
Why is the face not polished?
These cabochons are specifically offered in a rough finish: the crystal's striated texture is the primary attribute of the piece and part of its aesthetic proposal. The back is flat to facilitate mounting.
Is the black color natural or treated?
Black is intrinsic to the composition of Schorl: ferrous iron in its crystal structure absorbs all visible light. No detectable treatment.
What type of setting is rough Black Tourmaline suitable for?
We recommend a closed bezel setting in 925 silver, brass, or copper.
Are the dimensions exact?
The freeform shape with a rough surface implies natural variation: tolerance ±0.5 mm in any dimension. Each piece is individual; the indicated measurements are approximate. See the photographs for each variant for the specific piece.
Can these cabochons be polished once set?
Technically yes, although polishing while set is not the usual process. If you want a polished face, it is more advisable to purchase a polished cabochon directly.
How do you care for rough Black Tourmaline?
Clean with a soft brush and lukewarm water to remove dust from the striations. Avoid acids and ultrasonic cleaners. With a hardness of 7–7.5 Mohs, it is resistant to everyday scratches. More information on jewelry care.
See also: cabochon collection · silver smithing materials.
