Coccolithophore cells covered with calcium carbonate (chalk) scales. Progress in understanding the unique physiology of these globally important organisms will help us to understand how they may respond to changing ocean chemistry.
Calcium Carbonate - Botanical Colors
Chalk,assorted colours/BOX-100
Calcium Carbonate (Chalk) | Malthouse
Calcium Carbonate - Ultra Fine Chalk Powder | eBay
Buy chalk lumps for food - to saturate your body with calcium for little money.
Calcium Carbonate 50g
A crystal clear view of chalk formation | Max-Planck-Gesellschaft