Dhulka diatomaceous waa nooc ka mid ah dhagaxa siliceous ee bayoolojiga ah, oo inta badan ka kooban haraaga diatom-ka qadiimiga ah. Halabuurka kiimikada ee uu sameeyay inta badan waa SiO2, oo ka kooban xaddi yar oo Al2O3, Fe2O3, CaO, MgO, K2O, Na2O, P2O5 iyo walxo dabiici ah. Isticmaalka ugu weyn ee diatomite waa qalabka shaandhaynta, buuxinta, nuugayaasha, sidayaasha kicinta, agabka dhismaha ee deegaanka u fiican iyo wixii la mid ah.