calcium carbonate iglesias Mineral minerals pisoids pisolite pisolith quarry rare samples Sardinia sulcis abstract background bathroom ceramic clay cover decor decoration decorative effect fired floor flooring kitchen marble marbled material pattern stone texture tile wall appearance breakable broken brown calcification calcium-carbonate color colors colour colours cook cooking dried dry egg egg-shells eggs eggshells empty external food fragile fragility fragmentary fragments hard-shelled hollow idiomatic-expressions idioms inside internal leftover leftovers life outer-covering outside oval ovoid Remains scattered scattering speckled surface surfaces textures white yolk