 The surface composition of Ceres is broadly similar to that of C @-@ type asteroids . Some differences do exist . The ubiquitous features in Ceres ' IR spectrum are those of hydrated materials , which indicate the presence of significant amounts of water in its interior . Other possible surface constituents include iron @-@ rich clay minerals ( cronstedtite ) and carbonate minerals ( dolomite and siderite ) , which are common minerals in carbonaceous chondrite meteorites . The spectral features of carbonates and clay minerals are usually absent in the spectra of other C @-@ type asteroids . Sometimes Ceres is classified as a G @-@ type asteroid . 
 The surface composition of Ceres <a href='drop_aux' title='1'><mark>is</mark></a>broadly similar to that of C @-@ type asteroids . Some differences do exist . The ubiquitous features in Ceres <a href='null_genetive' title='2'><mark>'</mark></a>IR spectrum <a href='drop_aux' title='3'><mark>are</mark></a>those of hydrated materials , which indicate the presence of significant amounts of water in its interior . Other possible surface constituents include iron @-@ rich clay minerals ( cronstedtite ) and carbonate minerals ( dolomite and siderite ) , which <a href='drop_aux' title='4'><mark>are</mark></a>common minerals in carbonaceous chondrite meteorites . The spectral features of carbonates and clay minerals <a href='drop_aux' title='5'><mark>are</mark></a>usually absent in the spectra of other C @-@ type asteroids . Sometimes Ceres is classified as a G @-@ type asteroid . 
The surface composition of Ceres broadly similar to that of C @-@ type asteroids . Some differences do exist . da ubiquitous features in Ceres  IR spectrum those of hydrated materials , which indicate the presence of significant amounts of water in its interior . Other possible surface constituents include iron @-@ rich clay minerals ( cronstedtite ) and carbonate minerals ( dolomite and siderite ) , which common minerals in carbonaceous chondrite meteorites . The spectral features of carbonates and clay minerals usually absent in the spectra of other C @-@ type asteroids . Sometimes Ceres is classified as a G @-@ type asteroid .