inorganic chemistry - Can glass be made with anorthite?

The lunar highlands are made mostly of anorthosite (90% anorthite, the rest oxides of magnesium, iron, a little titanium, and traces of others), and pretty pure anorthite ($\ce{CaAl2Si2O8}$) is common. No minerals that are more than about half silica are known. The use of typical batch reactions to purify chemicals is (mostly) not practical on the Moon, as there is no water*, no halogens, and no carbon, nitrogen, or hydrogen.

Human habitats are going to need clear glass, the more the better. If the Moon was being settled, a way to make clear glass locally would be a priority. There are of course many things to be considered about the proper use of glass, but that is a separate issue. This question is about an advanced colony, not the first few habitats. You can assume the infrastructure for an involved process is available.

Could anorthite be processed into decent clear glass? How much impurity could it have? How can I look into the properties it might have and things to consider about the process?

Below is a table from the Lunar Sourcebook, Ch. 5 pg 129, showing percentages of pure anorthite in various minerals mixed in igneous rocks from the highlands:

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*Actually there is a lot of frozen water and other volatiles at the poles, but getting it in quantity is a big challenge, and it isn't found anywhere else.