Meanings of pure carbonate in English

All sorts of limestones are composed of more or less pure carbonate of lime.

It is a pure carbonate of lime, a creamy white deposit formed from dripping water, in stratified form, with cavities and fissures lined with crystals.

0.3445 gram of pure carbonate of lime gave 74.1 c.c.

Pure phosphate and nitrate of ammonia produce (though more slowly) the same effect, as does pure carbonate of soda.

0.2405 gram of pure carbonate of lime was then taken, and treated in the same way; 50.5 c.c.

I compared it with similar minute portions of the pure carbonates of potash, and similar minute portions of the pure carbonates of potash and soda.