Lithothamnion calcareum is a red seaweed also known as Phymatolithon calcareum or simply Pallas. The main difference of Pallas from other algae is the appearance of calcium and magnesium carbonates in the cell membranes, playing a role of a skeleton of the seaweed. These natural crystals (calcites) have been used as an exfoliant called "Maërl."
Besides high calcium and magnesium contents, Phymatolithon calcareum extract is rich in minerals like iron, manganese, boron, nickel, copper, and zinc, which have an essential role in skin moisturization and fiber cross-linking.
Lithothamnion calcareum extract contains bioactive compounds, including polyphenols and terpenes, with excellent antioxidant properties, protecting skin from free radicals and oxidative stress. In addition, this ingredient is well-studied and sold as a food supplement (under the name Aquamin). Thus it's safe, natural, and effective for skincare formulations.