Round black sunstone cabochon with faceted top surface, 10 mm diameter. The faceting amplifies the aventurescence effect: golden and coppery sparkles emerge from the opaque black base when exposed to direct light. Three variants available.
Item details
| Mineral |
Black sunstone (feldspar with hematite or iron oxide inclusions) |
| Dimensions |
10 mm diameter. Variation ±0.5 mm |
| Shape and back |
Round with faceted top surface, flat polished back |
| Finish |
Polished facet (top surface) + mirror polish (back) |
| Hardness |
6-6.5 Mohs — we recommend a closed bezel setting to protect the edge |
| Origin |
Material acquired in lapidary wholesale market |
| Treatment |
Untreated |
| Item type |
Available in 3 variants |
About this specific piece
Black sunstone is a feldspar (generally oligoclase or dark labradorite) with a high concentration of hematite or goethite inclusions oriented in preferred crystallographic planes. These inclusions produce a metallic aventurescence effect — golden, coppery, or reddish flashes — that contrasts with the dark base in a particularly dramatic way.
The faceting on the top surface multiplies the reflection angles of the inclusions: where a smooth cabochon would yield a single plane of sparkle, the faceting produces multiple simultaneous flashes from different facets. The result is a "star field" effect visible under direct lighting conditions. Three variants of the lot feature medium-high aventurescence intensity.
How aventurescence forms in black sunstone
Conventional sunstone (orange-peach) and black sunstone are feldspars from the same mineralogical group but with slightly different compositions. In the black variety, the iron oxide inclusions (hematite Fe₂O₃ or goethite FeO(OH)) are more abundant and are oriented in thin lamellae subparallel to crystallographic planes of the feldspar.
For which setting it works
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Bezel setting (925 silver or other precious metals) — a 10 mm closed bezel in 925 silver with an oxidized (black) finish creates a minimal chromatic contrast that draws all attention to the golden flashes of the stone; the smooth bezel emphasizes the black-gold contrast.
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Statement rings — the 10 mm size is large enough for a cocktail ring.
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Wire wrap — an alternative for those who work with wire; the round 10 mm format allows for symmetrical wrapping with 20 gauge wire.
Sunstone in lapidary tradition
Sunstones were valued by Norse and Viking cultures, who used them as "navigation stones" to locate the sun on cloudy days — although the stone used in that context was probably cordierite (iolite), not feldspar.
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 sunstone
Genuine sunstone shows aventurescence with clear angular variation: the metallic flash appears only from certain angles of direct illumination. Imitations in glass or black resin have more uniform or absent mica flashes. Under magnification, the surface of the sunstone exhibits feldspar cleavage (two cleavage planes) and the hematite lamellae are visible as sparkling flakes.
Frequently asked questions
What is the difference between the three variants?
Each variant is an individual piece with its own aventurescence distribution pattern. The subtle differences between No.1, No.2, and No.3 are reflected in the product photographs — each one shows the flashes in a slightly different distribution.
Is it treated?
Untreated. The aventurescence effect and black color are the result of natural iron oxide inclusions. Statement based on lapidary observation; the piece does not include formal gemological certification.
More about sunstone: properties and uses of sunstone. See also: cabochon collection · handmade rings.
