Most of the world's phosphate deposits can be grouped into six type*2 1) igneous apatite deposits| 2) marine phosphorites; 3) residual phosphorites j 4) river pebble deposits; 5) phosphatized rock2 and 6) guano. The igneous apatites and marine phosphorites form deposits measurable in millions or billions of tons; the residual deposits are measurable in thousands or millions 5 and the other types generally only in thousands of
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.