RocksdayMuscovite vs Phlogopite
To tell Muscovite from Phlogopite: Muscovite is colorless to pale silver, not bronze.
Light-colored mica that peels into paper-thin, transparent and flexible sheets. Its flakes are what make many rocks glitter.
Photo: Robert M. Lavinsky, CC BY-SA 3.0
The brown magnesium mica. Thin sheets bend and spring back, like muscovite, but the color is bronze rather than pale.
Photo: Géry PARENT, CC BY-SA 3.0
Key differences
- Muscovite is colorless to pale silver, not bronze.
Side by side
| Property | Muscovite | Phlogopite |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 2–2.5 | 2–2.5 |
| Luster | Vitreous to pearly | Pearly to vitreous |
| Streak | White | White |
| Colors | Clear, Silver, Brown | Brown, Yellow, Green |
| Crystal system | Monoclinic | Monoclinic |
| Specific gravity | 2.76–2.88 | 2.78–2.85 |
| Formula | KAl₂(AlSi₃O₁₀)(OH)₂ | KMg₃(AlSi₃O₁₀)(OH)₂ |
| Found in | Pegmatites of North Carolina; New Hampshire | Franklin, New Jersey; Ontario, Canada |
Properties that are the same for both are grayed out.
How to identify muscovite
- Peels into thin sheets that spring back when bent.
- Transparent to silvery and sparkly.
- Soft — scratched by a fingernail across the sheets.
- Stacked 'books' of sheets in pegmatites.
Crystal system: Monoclinic
Full Muscovite guide →How to identify phlogopite
- Bronze or yellow-brown flexible sheets.
- A fingernail scratches it.
- Sheets spring back when bent, unlike gypsum.
Crystal system: Monoclinic
Full Phlogopite guide →More comparisons
Frequently asked questions
What is the difference between muscovite and phlogopite?
Muscovite is a mineral with a Mohs hardness of 2–2.5 and a vitreous to pearly luster, usually colorless, silvery or brown. Phlogopite is a mineral with a Mohs hardness of 2–2.5 and a pearly to vitreous luster, usually brown, yellow or green.
How can you tell muscovite from phlogopite?
Muscovite is colorless to pale silver, not bronze.
Could you tell them apart from a blurry close-up?
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