Yes, mica is a Scrabble word!
...and is worth 8 points in Scrabble, and 10 points in Words with Friends
mica
Noun
1. Any of various minerals consisting of hydrous silicates of aluminum or potassium etc. that crystallize in forms that allow perfect cleavage into very thin leaves; used as dielectrics because of their resistance to electricity
What Scrabble words can I make with the letters in mica?
3 Letter Words
2 Letter Words