The main sources of phosphates and P are the phosphate beds of South Carolina, the apatite beds of Canada, and the bones of animals.
"An Introduction to Chemical Science"
R.P. Williams
A representative selection of the above stones, each with a sharp edge, is kept for the purpose of scratching and being scratched, and those usually set apart for tests in the various groups, are as follows:- 1 Talc 2 Rock-salt, or Gypsum 3 Calcite 4 Fluorspar 5 apatite 6 Felspar 7 Quartz 8 Topaz 9 Corundum 10 Diamond The stone under examination may perhaps first be somewhat roughly classified by its colour, cleavage, and general shape.
"The Chemistry, Properties and Tests of Precious Stones"
John Mastin
Both these rocks are composed of triclinic feldspar and augite with more or less olivine, magnetic or titaniferous oxide of iron, and usually a little nepheline, leucite, and apatite; basalt usually contains considerably more olivine than melaphyre, but chemically they are closely allied, although the melaphyres usually contain more silica and alumina, with less oxides of iron, lime, and magnesia, than the basalts.
"The Student's Elements of Geology"
Sir Charles Lyell