Volumetric (titrimetric) analysis — specifically EDTA complexometric titration — is the standard and most widely used method for determining Ca²⁺ content in carbonate rocks. Ca²⁺ is titrated with EDTA (ethylenediaminetetraacetic acid) using Eriochrome Black T or Murexide indicator at appropriate pH. Flame photometry (AAS) is also used but requires dissolution and instrumentation. Gravimetric methods are less efficient for routine Ca determination.