Freeform chrome chalcedony (mtorolite) cabochon, between 22 and 39 mm long and 5 mm dome height. The intense green is one of the most saturated in quartz minerals: it comes from trivalent chromium incorporated into the silica structure.
Piece Details
| Mineral |
Chrome chalcedony — mtorolite (microcrystalline SiO₂ with traces of Cr³⁺) |
| Dimensions |
22-39 × 15-22 × 5 mm (selectable by variant number); tolerance ±0.5 mm |
| Shape and Back |
Freeform, flat back |
| Finish |
Mirror polish |
| Hardness |
6.5–7 Mohs — suitable for rings and pendants; we recommend closed bezel setting |
| Origin |
Zimbabwe (Mtoroshanga deposits) · Material acquired in wholesale lapidary market |
| Treatment |
No treatment |
| Piece Type |
Selectable by variant number |
This specific piece
The chrome chalcedony in this lot features the saturated green characteristic of Zimbabwe mtorolite, with slight variations in hue—from lime to forest green—depending on the depth of the cut. Translucency is moderate: under direct light, the microcrystalline structure of quartz is visible, without the complete opacity of jade or the transparency of glass.
How mtorolite color forms
Chrome chalcedony forms when chromium-rich hydrothermal waters circulate through fissures in ultramafic rocks (peridotites, dunites) and deposit microcrystalline silica. The Cr³⁺ ion, responsible for the green color in emeralds and uvarovite garnet, is incorporated into the silica lattice during precipitation. The main deposits are found in Zimbabwe—especially around Mtoroshanga, from which the trade name "mtorolite" is derived—and in South Africa. The concentration of chromium determines the saturation of the green: pieces with more than 0.5% Cr₂O₃ achieve the deepest green.
What mounting it works for
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Closed bezel setting (925 silver or other precious metals) — with a hardness of 6.5-7 Mohs, mtorolite tolerates daily wear well. The saturated green contrasts dramatically with bright silver and yellow gold.
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Statement rings and large pendants — pieces 33-39 mm are ideal for cocktail rings or single focal point pendants.
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Wire wrap — the flat back and mineral's durability make it easy to wrap in any gauge.
Chalcedony in lapidary tradition
Green chalcedony—in its various varieties—was one of the first stones used in seals and amulets in the ancient Mediterranean. Romans imported green chalcedony from North Africa for intaglios.
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 chrome chalcedony
Authentic mtorolite has a characteristic translucency: under intense spotlight, the interior of the mineral is visible without being transparent. The green is homogeneous but not absolutely uniform—there are subtle gradations. The high hardness (6.5-7 Mohs) distinguishes it from dyed howlite (3.5 Mohs) and green glass (more uniform and perfect luster). The fracture is conchoidal and vitreous.
Frequently Asked Questions
Is it natural untinted chalcedony?
Yes. The intense green comes from naturally occurring trivalent chromium incorporated into the silica during its geological formation. No detectable treatment. Statement based on lapidary observation; the piece does not include formal gemological certification.
What is the difference between mtorolite and green jade?
Mtorolite is chalcedony (microcrystalline quartz), while jade can be jadeite (pyroxene) or nephrite (amphibole). Mtorolite has a more vitreous luster and different translucency; jadeite has a more granular texture under magnification. Both can have very similar greens to the naked eye.
Is it suitable for daily wear in rings?
With 6.5-7 Mohs, mtorolite is one of the hardest chalcedonies and tolerates daily use well with a closed bezel setting that protects the stone's edge.
See also: all cabochons · handmade rings · handmade pendants.
