Calcite

Calcite (calcium carbonate) is primarily an inert mineral filler/opacifier or mild abrasive, typically used at low-to-moderate percentages in powders, creams, and some cleansers. Clinical experience and patch testing data suggest it has low intrinsic irritancy, but its particulate/abrasive nature can aggravate compromised barriers (eczema, post-procedure) via mechanical irritation, especially with friction. Given sensitive-skin safety priorities, I rate it very gentle but not fully inert. Safety Notes: In commercial skincare, calcite (calcium carbonate mineral) is most often used at trace-to-low levels (~0.01–1%) as a mineral filler/opacifier or to support sensorial/soft-focus effects in leave-on creams and makeup-adjacent skincare. Mid-level use (1–15%) is common in rinse-off cleansers and scrubs where it contributes mild abrasive/polishing and bulking. The highest consumer-available levels are found in high-solids powdered cleansers, polishing masks, and tooth/skin-adjacent paste products where calcite can function as the primary abrasive/bulking phase, reaching ~30–70% depending on format; higher levels are limited by spreadability, grittiness, and suspension stability in conventional emulsions.