The facts
What psilomelane actually is
Psilomelane is classified as field term for botryoidal manganese oxides, chiefly romanèchite, with the composition Mixture dominated by (Ba,H₂O)₂Mn₅O₁₀. It crystallises in the cryptocrystalline aggregate system.
Colour comes from mn³⁺ and Mn⁴⁺ give an opaque steel-black with a metallic to silky lustre, which is also what a laboratory looks at when it is asked whether a colour is natural.
Specific gravity around 4.4–4.7. Cleavage: none. Those three numbers separate it from most of what imitates it.
Where psilomelane comes from
Psilomelane is produced at Romanèche-Thorins, Saône-et-Loire, France, Schneeberg, Saxony, Germany and Lake Valley, Sierra County, New Mexico, USA.
The locality is part of the description, not a footnote — two stones of the same weight from two of these places are not the same stone.
How psilomelane is treated
Untreated. A field name rather than a species — modern reports will call the crystalline part romanèchite. The banded silky material takes a mirror polish and is cut as cabochons and inlay.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What psilomelane is confused with
In the trade psilomelane is most often mistaken for, or substituted by, Hematite, Romanèchite, Goethite or Obsidian.
Because the material is opaque, refractive index is no help. Specific gravity around 4.4–4.7, hardness of 5–6, streak and magnification do the work instead.
What psilomelane is used for
Demand for psilomelane comes from mineral collecting, jewellery, architecture and interiors and pigments, which is why one price per carat never covers it.
We quote each application in the unit that trade actually buys in, by the specimen, by the carat or by the square metre.
Durability and care
Hardness 5–6; cleavage none. That combination decides what it can safely be set into.
Below about 5.5 a stone will be scratched by ordinary household dust, which is largely quartz. That does not make it unusable — it makes it a pendant, an earring or an object rather than a ring worn every day.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What psilomelane costs
As a guide, psilomelane trades around Cabochons 10–60 USD; slabs 10–50 USD/kg.
That is a range, not a quote. Colour, size, clarity, cut and origin move the figure a long way inside it, and the only honest price is one given against a specific stone. Send us what you need and we will price it.
Questions
Is psilomelane treated, and how?
Untreated. A field name rather than a species — modern reports will call the crystalline part romanèchite. The banded silky material takes a mirror polish and is cut as cabochons and inlay.
Where does psilomelane come from?
Romanèche-Thorins, Saône-et-Loire, France, Schneeberg, Saxony, Germany and Lake Valley, Sierra County, New Mexico, USA. Origin affects price, so we name the locality rather than the country on every quote.
Is psilomelane hard enough to wear every day?
Not really. At 5–6 on the Mohs scale it is softer than the quartz dust in ordinary household dirt, so it scratches with wear. It suits pendants, earrings and objects better than a daily ring.
How much does psilomelane cost?
Indicatively Cabochons 10–60 USD; slabs 10–50 USD/kg. Colour, size, clarity and origin move the price a long way within that, so treat it as a range and ask for a quote against a specific stone.
What is psilomelane confused with?
Most often Hematite, Romanèchite, Goethite and Obsidian. Since the material is opaque, separation relies on specific gravity near 4.4–4.7, hardness and magnification.
What is psilomelane used for besides jewellery?
mineral collecting, architecture and interiors and pigments. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for psilomelane?
Tell us the size, the quality and what it is for. We source it, photograph it and quote it — with the locality named.
Ask about psilomelane