I like shiny stuff. If it shines, it is agreeable with my emotional state. Thus, I collect shiny stuff. If it does not shine, I may or may not collect it. Some things that lack shine are required for life, such as unpolished shiny things. A little Nev-r Dull will solve these, so I still like them.
Specific shiny stuff I collect include gold, platinum, silver, gallium, copper, brass, tin.