Common Name(s): Expanded perlite,volcanic glass,obsidian powder

CAS Number: 93763-70-3

DESCRIPTION

What It Does: Provides ultra-lightweight texturizing and oil absorption from expanded volcanic glass.

Why It's Used: Lightest cosmetic powder — perlite's expansion (20× volume increase from volcanic glass heating) creates the lightest, most porous powder mineral available for ultra-lightweight mattifying formulations.

How It Works: Volcanic obsidian glass heated to 900°c expands to 20× original volume creating porous lightweight particles. very low bulk density (~100 g/l vs talc's 850 g/l) creates extremely lightweight powder feel. surface area provides sebum absorption. inert amorphous silica structure.

Typically Found In: Ultra-lightweight foundations,mattifying primers,setting powders

TECHNICAL DETAILS

Primary Category: Functional – volcanic glass additive

Secondary Functions: Skin conditioning

Application Areas:

Typical Concentration Range: 1%–20%

SOURCING & ETHICS

Vegan Status: Conditional - supplier confirmation required

Halal Status: Unverified - supplier confirmation required

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier. [audit 2026-07-29 rev2: the record's own source_notes does not assert a non-animal origin, or instructs the reader to verify with the supplier; "yes" asserts knowledge the record does not hold. determination requires shariah-panel sign-off.]

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Perlite's expansion mechanism is uniquely volcanic: obsidian contains 2-5% water trapped from submarine volcanic eruption. when rapidly heated, this trapped water vaporises and expands within the softened glass, creating foam-like structure with hundreds of sealed pores. this internal foaming from historic volcanic hydration is what gives cosmetic perlite its uniquely low density.

Last Verified: 2026-03-12

Primary Sources: Cosing database,cir safety assessment