Boundary
A paper block is not a real grain or identified mineral.
Complete source
Fictional postcard has a rock outline filled with big pale/dark paper blocks. Historical U02 E3 describes minerals as rock components; no component names are given here.
Invitation
Write or direct a components caption and a question about the unnamed blocks.
Next try
Compare a second differently coloured model while keeping both identities open.
Ordinary possible response
The paper blocks model components; this picture cannot name their minerals.
Title
Rock components postcard