Identification clues
Calcite can be clear, white or coloured by other material. It has strong cleavage and can show flat, slanted break surfaces. Growth faces, polishing and cleavage are different things; do not break a specimen to look for them.
Mineral facts and formation
Calcite is a major constituent of limestone and marble and also occurs in veins and cave deposits. Its many crystal habits make shape a helpful observation rather than a single definitive test.
Lookalikes and useful comparisons
Clear Calcite can resemble Clear Quartz, but their reference hardnesses and cleavage differ. “Caribbean Calcite” is a commercial label; this general calcite entry does not certify the composition or origin of the collection specimen.
Care for a display specimen
Protect it from knocks and harder stones. Use a soft dry cloth for display pieces and avoid acidic cleaners. Do not apply vinegar or other acids as a home identification exercise.
Look a little closer
Try this observation.
Look at an existing flat surface and describe its angle and shine. Record whether it might be a cut surface, a growth face or a break surface; leave the explanation open if you cannot tell.
Does every piece of calcite glow under UV?
No. Fluorescence varies. A glow is an observation to record alongside the lamp conditions, not a guarantee supplied by the mineral name.
Sources and further reading
Reference information checked 29 September 2026. These sources describe minerals generally; they do not identify a particular stone.