Question

Which mineral forms the majority of granite: biotite mica, quartz, or feldspar?

Answer 1

Granite is mostly feldspar. Quartz comes in second.

Explanation:

By definition, granite may contain up to 65% "alkali feldspar"; the "alkali" here means the feldspar contain alkali metals like sodium and potassium.

See https://en.wikipedia.org/wiki/Granite for more details.