Potassic-chloro-hastingsite (original) (raw)

Formula:

KCa2(Fe2+4Fe3+)(Si6Al2)O22Cl2

Colour:

Greenish black, dark green

Crystal System:

Monoclinic

Name:

It was originally named dashkensanite in 1936, and discredited as a variety of hastingsite in 1978. It was revalidated and renamed chloro-potassichastingsite in 2005. The current naming follows the most recent amphibole nomenclature of 2012.

The name chloro-potassichastingsite has also been used for this mineral. The 2012 amphibole nomenclature follow the principle that the various prefixes to the root name are listed in order it occurs in the formula. The approved name for this mineral is consequently potassic-chloro-hastingsite.

The hastingsite-group minerals are defined with 0.5 < A(Na+K+2Ca)<1.5 where Na or K is dominant and with the C position occupied by Mg or Fe2+ as dominant divalent ions and 0.5 < C(Al+Fe3+ +2Ti) < 1.5 where Fe3+ is dominant. W may contain (OH),F or Cl.

Potassic-chloro-hastingsite is defined with:

A position: K dominant
C position: Fe dominant divalent ion
W position: Cl dominant

Crystal System:

Monoclinic

Class (H-M):

2/m - Prismatic

Cell Parameters:

a = 9.964 Å, b = 18.31 Å, c = 5.351 Å
β = 105°

Ratio:

a:b:c = 0.544 : 1 : 0.292

Unit Cell V:

942.98 ų (Calculated from Unit Cell)

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.