Giorgio Armani Quarzo (2) is a cool taupe with a metallic finish that is limited edition and retails for $34.00. In comparison, Guerlain Amber Silver (05) is a warm taupe with a metallic finish that is permanent and retails for $30.00.
Guerlain Amber Silver (05) is 85% similar — it is more shimmery, warmer, less glossy.