CAS 471-34-1 appears in our catalog under these names: Calcium carbonate, Puratronic½, 99.99% (metals basis) , Calcium carbonate, ACS, 99.0% min , Calcium carbonate, ACS, low in alkalies, 99.0% min , Calcium carbonate, chelometric standard, ACS, 99.95-100.05% , Calcium carbonate, Puratronic®, 99.999% (metals basis) . Offered by: Thermo Scientific (Alfa Aesar). Available pack sizes: 5g, 25g, 100g, 500g, 250g, 1kg, 2kg.