Use XRF or another technique. XRD will not be sensitive to less than 1% or so of other components. It’s used to identify the major phases in a system not for elemental analysis.

Dear Vignesh Manoharan ,

what compounds do you expect other than Calcium carbonate?

and please comment on why you expect them...

The other phase(s) might be too tiny in concentration (as Alan F Rawle indicated by the '1%') and/or they might be amorphous.

You should share your XRD pattern...

Best regards

G.M.

Make sure the expected phase is not amorphous; if yes, try another analysis technique (NMR, IR), if not, try zooming on the vertical axis.