This calcite is 4% molar magnesium, as seen by XRD peak shifts.
1000x magnification
This calcite is 4% molar magnesium, as seen by XRD peak shifts.
1000x magnification
Twinned calcite crystals from Ranu Klakah a crater lake in eastern Java cored by Ed Cushing and Shelly Crausbay of the University of Minnesotta.