Feldspar polymorphs

Hollandite-type NaAlSi3O

Mineral name:  lingunite (named after Lin-gun Liu)

Discovery:  Sixiangkou meteorite (L6), Tenham meteorite (L6)

A fine-grained aggregate of lingunite in the Y-75100 chondrite. 

*References*

Hollandite-type KAlSi3O8 

Mineral name:  liebermannite (named after Robert C. Liebermann)

Discovery:  Zagami meteorite (shergottite)

*References*

Hollandite-type CaAl2Si2O8 

Mineral name:  stöfflerite (named after Dieter Stöffler)

Discovery:  NWA 856 (shergottite)

*References*