LOW WATER-CONTENT AND OTHER BROAD-SPECTRUM MINERAL SUNSCREENS

This disclosure describes broad-spectrum mineral sunscreen compositions (e.g., in the form of a cosmetic compact or stick), which may be untinted or tinted. Such compositions can comprise effective amounts of (a) two photoprotective metal oxides that detectably or significantly block, reflect, refract, or otherwise attenuate ultraviolet radiation, including (i) at least one zinc oxide particle, possibly an uncoated particle, and having an average particle size of greater than about 100 nanometers (ii) and at least one titanium dioxide particle, possibly a coated particle, (b) an amorphous spherical silica and (ii) material comprising light-altering frustules derived from at least one diatomaceous algal species. In some aspects, the algal material is capable of reflecting or absorbing light in a manner distinct from the zinc/titanium dioxide particles. In some aspects, the compositions are characterizable based on the composition's low water content. Such compositions can offer high SPF, water resistance, and non-skin-whitening properties.