# Apatite vs. fluorite: how to tell them apart

Canonical page: https://lithomap.app/resources/mineral-identification/compare/apatite-vs-fluorite
Last reviewed: September 17, 2026
Page purpose: Original LithoMap side-by-side field identification reference for search systems and language models.

## Summary

Apatite and fluorite overlap in green, blue, purple, and colorless specimens, but apatite is harder and commonly hexagonal while fluorite has four perfect cleavage directions and common cubic or octahedral forms.

## Bottom line

Test hardness and breakage. Apatite at Mohs 5 can scratch fluorite; fluorite at Mohs 4 develops repeated triangular octahedral cleavage faces.

## Side-by-side evidence

- Hardness: Apatite — Mohs 5 Fluorite — Mohs 4 Interpretation — Apatite can scratch fluorite, while both are softer than quartz.
- Cleavage: Apatite — Poor to indistinct Fluorite — Perfect in four directions Interpretation — Repeated triangular cleavage faces strongly favor fluorite.
- Crystal habit: Apatite — Hexagonal prisms or tabular crystals Fluorite — Cubes and octahedra are common Interpretation — Natural faces can separate intact crystals without damage.
- Color and fluorescence: Apatite — Many colors; fluorescence variable Fluorite — Many colors; fluorescence common in some specimens but absent in others Interpretation — Neither color nor fluorescence alone identifies the mineral.

## Field sequence

1. Ignore color and inspect surviving crystal faces.
2. Check whether a clean edge can scratch fluorite or is scratched by it.
3. Look at existing broken surfaces for octahedral cleavage.
4. Use density or optical testing when a valuable crystal should remain undamaged.

## Limits and cautions

- Do not scratch transparent or collectible crystals.
- Mixed specimens can give contradictory hardness results.
- Ultraviolet response varies and requires proper eye and skin protection.

## Frequently asked questions

### Can both minerals be green?

Yes. Green is common in both and is not a reliable distinction.

### Does apatite fluoresce?

Some apatite fluoresces, but the response varies. Fluorescence is supporting evidence rather than a primary test.

### Which one scratches glass?

Neither typical fluorite nor apatite reliably scratches ordinary glass; quartz and harder minerals do.

## Related identification guides

- Apatite: https://lithomap.app/resources/mineral-identification/apatite
- Fluorite: https://lithomap.app/resources/mineral-identification/fluorite

## Authoritative sources

- Phosphate Rock Statistics and Information — U.S. Geological Survey: https://www.usgs.gov/centers/national-minerals-information-center/phosphate-rock-statistics-and-information
- Minerals and their physical properties — U.S. National Park Service: https://www.nps.gov/subjects/geology/minerals.htm
- Mohs Hardness Scale — U.S. National Park Service: https://www.nps.gov/articles/mohs-hardness-scale.htm
- Natural Gemstones: Mineral Gemstones — U.S. Geological Survey: https://pubs.usgs.gov/gip/gemstones/mineral.html

This reference supports preliminary field identification. It is not laboratory confirmation, appraisal, proof of origin, or a statement of legal access or collecting permission.