Ingredient review
Biotite
INCI: Biotite
Biotite is a natural mineral that adds shimmer and color to makeup, but its iron content may cause discoloration in some formulations.
In plain English
Biotite is a type of mica, a mineral that gives makeup a sparkly or shimmery look. Unlike the more common clear mica, biotite is dark brown or black because it contains a lot of iron. It's used in products like eyeshadows and highlighters to create a subtle, metallic sheen. Because it's a natural mineral, it's generally considered safe for most skin types, but its dark color can sometimes make formulas look muddy or change color over time.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- natural
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Biotite is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Biotite.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
Biotite is a phyllosilicate mineral in the mica group, rich in iron and magnesium. It appears as dark, flaky crystals that can be ground into a fine powder for use as a pigment and shimmer agent in cosmetics.
How it works
In a cosmetic product, biotite particles reflect light, creating a shimmer or glitter effect. Its dark color also contributes to the overall shade of the product, often adding depth or a metallic finish. It sits on the surface of the skin or lips without being absorbed.
Pros
Natural shimmer
Biotite provides a soft, metallic sheen that is less glittery than synthetic options, making it ideal for everyday makeup looks.
Low irritation potential
As a natural mineral, biotite is generally well-tolerated and unlikely to cause breakouts or irritation for most users.
Cons and cautions
Potential discoloration
The high iron content in biotite can cause the product to change color over time or appear muddy in certain formulations, affecting the final look.
Limited versatility
Biotite's dark color restricts its use to deeper shades; it cannot replace clear or white shimmer agents in light-colored products.
Best for
- People who prefer natural mineral makeup
- Those looking for a subtle, non-glitter shimmer in eyeshadows or highlighters
Use caution if
- Individuals with very sensitive skin or known allergies to mica or iron compounds
Usage tips
Safety summary
Biotite is considered safe for cosmetic use at typical concentrations. The main concern is potential discoloration in formulas, not skin safety. It is non-toxic and non-irritating for the vast majority of users.
Research notes
There is limited peer-reviewed research specifically on biotite in cosmetics. Its safety is inferred from the general safety of mica minerals and iron oxides, which are well-studied and widely accepted as safe in topical applications.
Common label clues
- Typical concentration
- 1-10% in powder products
- Regulatory status
- Approved for use in cosmetics in the US (FDA) and EU (CosIng) as a colorant and opacifying agent, with no specific restrictions beyond general safety requirements.
- Common uses
- Eyeshadows, Lipsticks, Loose powders, Highlighters
- Environmental note
- Biotite is mined from natural deposits. Mining practices vary, and some sources may have environmental impacts. Look for brands that source mica responsibly.
Good to know
- Biotite is often listed simply as 'Mica' on ingredient labels, so check for the specific mineral type if you have concerns.
- It is not the same as synthetic mica (synthetic fluorphlogopite), which is more color-stable.
Common questions
What is Biotite in beauty products?
Biotite is a type of mica, a mineral that gives makeup a sparkly or shimmery look. Unlike the more common clear mica, biotite is dark brown or black because it contains a lot of iron. It's used in products like eyeshadows and highlighters to create a subtle, metallic sheen. Because it's a natural mineral, it's generally considered safe for most skin types, but its dark color can sometimes make formulas look muddy or change color over time.
What does Biotite do in a beauty product?
In a cosmetic product, biotite particles reflect light, creating a shimmer or glitter effect. Its dark color also contributes to the overall shade of the product, often adding depth or a metallic finish. It sits on the surface of the skin or lips without being absorbed.
Is Biotite safe for most people?
Biotite is considered safe for cosmetic use at typical concentrations. The main concern is potential discoloration in formulas, not skin safety. It is non-toxic and non-irritating for the vast majority of users.
Who should be careful with Biotite?
Individuals with very sensitive skin or known allergies to mica or iron compounds
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.