Ferristilpnomelane

Where it forms, where it's found

7recorded occurrences

Source · OpenStreetMap

Physical

Hardness: 1Talc
2Gypsum
3Calcite
4Fluorite
5Apatite
6Orthoclase
7Quartz
8Topaz
9Corundum
10Diamond
Transparency: Transparent · Translucent
Colour: Greenish brown to dark greenish brown or black
Streak: Dark greenish brown
Tenacity: flexible
Cleavage: Perfect
(001)
Fracture: Micaceous

Chemical composition

Constituent elements: Mass composition breakdown
Element Atoms At. mass g/mol Mass g/mol Mass share
26FeIron Iron 16 55.845 893.520
33.35%
8OOxygen Oxygen 54 15.999 863.946
32.25%
14SiSilicon Silicon 12 28.085 337.020
12.58%
13AlAluminium Aluminium 12 26.982 323.784
12.09%
12MgMagnesium Magnesium 8 24.305 194.440
7.26%
19KPotassium Potassium 1 39.098 39.098
1.46%
1HHydrogen Hydrogen 27 1.008 27.216
1.01%
Total 2679.024 100.00%
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
26FeIron	Iron	16	55.845	893.520	33.35%
8OOxygen	Oxygen	54	15.999	863.946	32.25%
14SiSilicon	Silicon	12	28.085	337.020	12.58%
13AlAluminium	Aluminium	12	26.982	323.784	12.09%
12MgMagnesium	Magnesium	8	24.305	194.440	7.26%
19KPotassium	Potassium	1	39.098	39.098	1.46%
1HHydrogen	Hydrogen	27	1.008	27.216	1.01%
	Total	2679.024	100.00%

Group, growth & confusion

1 mineral

Parsettensite(K,Na,Ca)_7.5(Mn,Mg)₄₉Si₇₂O₁₆₈(OH)₅₀ · nH₂O
Mineral
—

Literature, links & citation

Citations

—Winchell, Alexander N., 1951, Optical Mineralogy, fourth edition, part 2, p. 390.

Cite this entry

@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Ferristilpnomelane — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/ferristilpnomelane-10587},
  note      = {Accessed 2026-05-11}
}