Ammolite

Where it forms, where it's found

2recorded occurrences

Source · OpenStreetMap

Physical

Hardness: 1Talc
2Gypsum
3Calcite
4Fluorite
5Apatite
6Orthoclase
7Quartz
8Topaz
9Corundum
10Diamond
Colour: Iridescent colors of red · purple · blue · green · yellow
Interference is the most likely cause of color
Density: 2.76 g/cm³

Optical

UV response: Only yellow in fracture fillings.

Chemical composition

Constituent elements: Mass composition breakdown
Element Atoms At. mass g/mol Mass g/mol Mass share
8OOxygen Oxygen 3 15.999 47.997
47.96%
20CaCalcium Calcium 1 40.078 40.078
40.04%
6CCarbon Carbon 1 12.011 12.011
12.00%
Total 100.086 100.00%
Mass share = atoms × atomic mass ÷ molar mass × 100
From Mindat formula

Mass composition breakdown
Element	Atoms	At. mass g/mol	Mass g/mol	Mass share
8OOxygen	Oxygen	3	15.999	47.997	47.96%
20CaCalcium	Calcium	1	40.078	40.078	40.04%
6CCarbon	Carbon	1	12.011	12.011	12.00%
	Total	100.086	100.00%

Synonyms

Ammoliitti
Ammolit
Ammolita
Ammolith
Amolitas
Calcentit
Calcentita
Calcentite
Korit
Korita
Korite

Literature, links & citation

Citations

1986Pough, Frederick H. (1986) Ammolite. Grandmother-of-Pearl. Lapidary Journal, 39 (10). 35-41
2001Mychaluk, Keith A., Levinson, Alfred A., Hall, Russell L. (2001) Ammolite: Iridescent Fossilized Ammonite from Southern Alberta, Canada. Gems & Gemology, 37 (1) 4-25 doi:10.5741/gems.37.1.4DOI: 10.5741/gems.37.1.4
2005en.wikipedia.org (n.d.) https://en.wikipedia.org/wiki/Ammolite
2009Mychaluk, Keith A. (2009) Update on Ammolite Production from Southern Alberta, Canada. Gems & Gemology, 45 (3) 192-196 doi:10.5741/gems.45.3.192DOI: 10.5741/gems.45.3.192

Cite this entry

@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Ammolite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/ammolite-8393},
  note      = {Accessed 2026-05-11}
}