Calcite
Calcite is the most stable form of calcium carbonate. Samples of 13 Cenriched calcite have been studied by Phillips and coworkers. 74 The variation of the 13 C CPMAS signal as a function of the contact time resembles closely to what expected for an isolated 13 C– 1 H spin pair and therefore the extracted internuclear distance ( ± Å) provides a strong evidence for the presence of ...