Hello again,
i hope you having a great morning and thank you for asking how my morning too.
Feldspar is the most important mineral that makes up gneiss along with mica and quartz. Gneiss can be formed from a sedimentary rock such as sandstone or shale, or it can be formed from the metamorphism of the igneouse rock granite.
>magma "contacts" solid rock - heat is transferred into overlying rocks through conduction - changing the pre-existing rock it intruded.
> high heat/low pressure
> localized metamorphism
>"fast-acting," like touching a hot frying pan
*Country rock (surrounding) is baked from conduction
i hope this answer your question if not im so sorry
have great day
FaithRawlins14