Regerite (original) (raw)

Formula:

KFe6(PO4)4(OH)7(H2O)6 · 4H2O

Crystal System:

Monoclinic

Name:

Named in honor of the married couple Grete (b. 25 September 1948) and Werner (b. 4 June 1946) Reger from Pleystein, Germany. The couple manage the Stadtmuseum at Pleystein and show immense dedication to make known the minerals of Kreuzberg and Hagendorf to the public.

New structure type. Not unique in terms of chemical combination - compare, e.g., leucophosphite, gengenbachite, or haigerachite.

Structure details:
* heteropolyhedral layers || {100} made of Fe-centred octahedra and PO4 tetrahedra;
* edge-shared octahedral dimers connect the layers → slit-like channels || [001];
* K+ ions and water reside within these channels.

Crystal System:

Monoclinic

Class (H-M):

2/m - Prismatic

Cell Parameters:

a = 15.408(11) Å, b = 17.311(11) Å, c = 9.870(11) Å
β = 95.42(2)°

Ratio:

a:b:c = 0.89 : 1 : 0.57

Morphology:

Prisms with chisel-shaped terminations. The crystals are flattened on {100} and elongated along [001], and display the forms {100}, {010} and {011}.

General Appearance of Type Material:

Prisms, usually 5 to 20 µm wide & up to 0.1 mm long, forming clusters; flattened on {100}, elongated along [001], showing {100}, {010} and {011} forms.

Place of Conservation of Type Material:

Collections of the Mineralogical State Collection Munich (SNSB), Theresienstrasse 41, 80333 Munich, Germany, registration number MSM 38039.

Geological Setting of Type Material:

Associated Minerals at Type Locality: