from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A sedimentary rock consisting predominantly of apatite and other phosphates.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. a sedimentary rock rich in phosphate minerals such as apatite
from the GNU version of the Collaborative International Dictionary of English
- n. A massive variety of apatite.
from The Century Dictionary and Cyclopedia
- n. A name applied originally to a massive variety of apatite, but now used to embrace the more or less impure earthy to compact calcium phosphate which forms beds of considerable magnitude in some localities (Estremadura in Spain, Bohemia, etc.), and is of much economic importance.
Gypsum, phosphorite, and salt are the major minerals mined in the state; there are also small deposits of gold and silver.
Near shore and offshore sediments hold rich deposits of minerals (diamonds, phosphorite, diatomite), as well as oil and gas reserves.
Phosphate rock is formed in oceans in the form of calcium phosphate, called phosphorite.
This mineral is even less soluble than phosphorite, so that a direct application of apatite onto cultivated fields exhibits a fertilizing effect only after a period of 10 - 15 years.
This apatite, or phosphorite, is found in certain parts of the world in large masses; but as a rule, it only occurs in small quantities in most rocks.
We have already referred in Chapter V. to large deposits of apatite or phosphorite found in Canada.
Now, the solubility of Thomas-slag in citrate of ammonia was found by Professor Wagner to be no less than 74 per cent, while that of phosphorite only amounted to 4 per cent.
This was superseded by coprolites and Estremadura phosphorite, Suffolk coprolites being for many years the chief material employed.
Professor Fleischer has also tested the comparative solubility of basic slag and phosphorite, by boiling them in a solution of acetic acid.
Coarse fragments of bone, powdered phosphorite and coprolite, Thomas-slag, farmyard manure 33