9×7 mm (±0.5 mm) moss-blue kyanite oval cabochon in rose cut, 3-4 mm thickness.
Piece specifications
| Mineral |
Kyanite (Kyanite · Al₂SiO₅ — polymorph of sillimanite and andalusite) |
| Dimensions |
9×7 mm, oval freeform · thickness 3-4 mm · ±0.5 mm due to artisanal cutting |
| Shape and back |
Oval freeform, rose cut (domed facets), flat back |
| Finish |
Lapidary polish with rose facets |
| Hardness |
4.5-5 Mohs (⊥ c-axis) · 6-7 Mohs (∥ a-axis) — anisotropic hardness · we recommend closed bezel setting |
| Origin |
India |
| Treatment |
Untreated |
| Type of piece |
Available in various formats within the lot |
About this specific piece
The term "moss" refers to the kyanite's natural inclusions — veins, spots, or diffuse, fibrous-looking areas that resemble moss underwater.
Cutting kyanite into a rose cut requires careful stone orientation: the axis of lower hardness (perpendicular to the c-axis) cannot be along the facet edges, or they would chip off.
How blue kyanite's color forms
Kyanite is an aluminum silicate (Al₂SiO₅) that shares its formula with sillimanite and andalusite — they are three polymorphs of the same compound, stable under different temperature and pressure conditions.
What settings it works for
-
Rings with closed oval bezel in 925 silver — kyanite's anisotropic hardness makes a closed bezel essential for ring use: it protects the rose-cut edges from lateral impacts in the direction of lower hardness. The result in a statement ring is visually powerful.
-
Pendants with openwork setting or silver bezel — in pendants, the risk of impact is lower, and both closed bezel and openwork settings that leave the back visible can be used. Kyanite's deep blue works especially well with oxidized silver or aged silver.
-
Wire wrap — possible for experienced jewelers, but care must be taken to avoid pressing the wire against the facet edges in the direction of lower hardness. Cage or soft wrap techniques are most suitable.
Kyanite in lapidary tradition
The name "kyanite" comes from the Greek kyanos (dark blue), the same term that named the pigment cyan. In industrial mineralogy, kyanite is primarily used as a refractory raw material for high-temperature bricks — the mineral can withstand up to 1,400°C without degrading.
In crystal tradition, kyanite is associated with communication, mental clarity, and nervous system balance. It is considered one of the few stones that do not accumulate or retain negative energies. The symbolic properties attributed to minerals belong to cultural and historical traditions. They are shared for educational purposes, not as medical advice.
How to recognize genuine kyanite
The most distinctive characteristic of genuine kyanite is its anisotropic hardness: a steel needle can easily scratch kyanite in the direction of the c-axis (4.5-5 Mohs) but not perpendicular to it (6-7 Mohs).
Frequently asked questions
What does it mean for kyanite to have anisotropic hardness?
That its hardness varies depending on the direction it is measured: 4.5-5 Mohs perpendicular to the crystallographic c-axis and 6-7 Mohs parallel to the a-axis.
Are "mossy" inclusions a defect?
No. They are natural characteristics of the material that add character and identity to each piece.
Is it treated?
No detectable treatment. Statement based on lapidary observation; the piece does not include formal gemological certification.
Are the measurements exact?
9×7 mm is the reference measurement with a tolerance of ±0.5 mm in any dimension due to artisanal cutting.
Is it safe for an everyday ring?
With a well-executed closed bezel, yes. The bezel protects the rose-cut edges from impacts in the direction of lower hardness.
How is it cared for?
Manual cleaning with a soft, damp cloth. Avoid ultrasonic cleaners — fibrous inclusions can act as fracture initiation points under intense vibration. More tips in jewelry care.
See also: complete cabochon collection.
