The facts
What muscovite actually is
Muscovite is classified as muscovite (mica group), with the composition KAl₂(AlSi₃O₁₀)(OH)₂. It crystallises in the monoclinic system.
Colour comes from colourless to silvery when pure; green from Cr, pink from Mn, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.552–1.618. Specific gravity around 2.77–2.88. Cleavage: perfect basal {001} — splits into elastic transparent sheets. Those three numbers separate it from most of what imitates it.
Where muscovite comes from
Muscovite is produced at Minas Gerais, Brazil, Bihar and Andhra Pradesh, India, Spruce Pine, North Carolina, USA and Karelia, Russia.
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 muscovite is treated
Untreated. Historically glazed windows and stove doors thanks to its transparent heat-resistant sheets; today overwhelmingly an industrial and electrical insulation mineral. Cut only as a curiosity.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What muscovite is confused with
In the trade muscovite is most often mistaken for, or substituted by, Phlogopite, Lepidolite, Talc or Gypsum.
The separation is rarely a matter of opinion: refractive index 1.552–1.618 and specific gravity 2.77–2.88 settle most of it in a minute, and magnification settles the rest.
What muscovite is used for
Demand for muscovite comes from heavy industry, technical and precision components, mineral collecting and decorative objects, which is why one price per carat never covers it.
We quote each application in the unit that trade actually buys in, by the tonne, by the piece or by the specimen.
Durability and care
Hardness 2–3; cleavage perfect basal {001} — splits into elastic transparent sheets. 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 muscovite costs
As a guide, muscovite trades around Industrial pricing; negligible as a gem.
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 muscovite treated, and how?
Untreated. Historically glazed windows and stove doors thanks to its transparent heat-resistant sheets; today overwhelmingly an industrial and electrical insulation mineral. Cut only as a curiosity.
Where does muscovite come from?
Minas Gerais, Brazil, Bihar and Andhra Pradesh, India, Spruce Pine, North Carolina, USA and Karelia, Russia. Origin affects price, so we name the locality rather than the country on every quote.
Is muscovite hard enough to wear every day?
Not really. At 2–3 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 muscovite cost?
Indicatively Industrial pricing; negligible as a gem. 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 muscovite confused with?
Most often Phlogopite, Lepidolite, Talc and Gypsum. A refractive index of 1.552–1.618 and a specific gravity near 2.77–2.88 separate it quickly.
What is muscovite used for besides jewellery?
heavy industry, technical and precision components, mineral collecting and decorative objects. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for muscovite?
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 muscovite