Písekite-(Y)

Where it forms, where it's found

1recorded occurrences

Source · OpenStreetMap

Radioactivity

Physical

Hardness: 1Talc
2Gypsum
3Calcite
4Fluorite
5Apatite
6Orthoclase
7Quartz
8Topaz
9Corundum
10Diamond
Colour: Yellowish brown to black
Streak: Gray
Fracture: Conchoidal
Density: 4.032 g/cm³

Crystallography

Morphology: Crystals elongated [010] and flattened (100).

Chemical composition

Constituent elements: Mass composition breakdown
Element Atoms At. mass g/mol Mass g/mol Mass share
92UUranium Uranium 1 238.029 238.029
26.94%
73TaTantalum Tantalum 1 180.948 180.948
20.48%
41NbNiobium Niobium 1 92.906 92.906
10.52%
39YYttrium Yttrium 1 88.906 88.906
10.06%
33AsArsenic Arsenic 1 74.922 74.922
8.48%
8OOxygen Oxygen 4 15.999 63.996
7.24%
26FeIron Iron 1 55.845 55.845
6.32%
22TiTitanium Titanium 1 47.867 47.867
5.42%
20CaCalcium Calcium 1 40.078 40.078
4.54%
Total 883.497 100.00%
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
92UUranium	Uranium	1	238.029	238.029	26.94%
73TaTantalum	Tantalum	1	180.948	180.948	20.48%
41NbNiobium	Niobium	1	92.906	92.906	10.52%
39YYttrium	Yttrium	1	88.906	88.906	10.06%
33AsArsenic	Arsenic	1	74.922	74.922	8.48%
8OOxygen	Oxygen	4	15.999	63.996	7.24%
26FeIron	Iron	1	55.845	55.845	6.32%
22TiTitanium	Titanium	1	47.867	47.867	5.42%
20CaCalcium	Calcium	1	40.078	40.078	4.54%
	Total	883.497	100.00%

In other languages

German: Písekit-(Y)
Italian: písekite-(Y)

Classification

Strunz

10th ed.

4.00

4OxidesClass
4.0— unnamed intermediate level —Division
4.00— unnamed intermediate level —Group
4.00Písekite-(Y)Species

Literature, links & citation

Citations

1923Krejči (1923), Časopis Min. Geol. Prague: 1: 2.
1936Nováček (1936), Vĕda Příodin Jahrg.: 17: 1. - Min. Abs. (1937): 6: 507.
1944Palache, Charles, Berman, Harry, Frondel, Clifford (1944) The System of Mineralogy (7th ed.) Vol. 1 - Elements, Sulfides, Sulfosalts, Oxides. John Wiley and Sons, New York.
1972Lithos (1972): 5: 93-103.
2001Strunz, Hugo, Nickel, Ernest H. (2001) Strunz Mineralogical Tables (9th ed.) Schweizerbart.

Cite this entry

@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Písekite-(Y) — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/pisekite-y-29146},
  note      = {Accessed 2026-05-11}
}