Rare gems and precious metals, made into fabulous designs by renowned craftsmen, have often served as symbols of wealth and power.

FORBES: Boston MFA to Open New Gallery with Jewelry Exhibit

Recycling hazardous electronic equipment for material recovery (e.g. rare earth, and precious and other metals) in a manner which can substantially mitigate the hazards, entails significant costs.

FORBES: It's Easy Enough To Solve The Problem Of E-Waste

Asteroids could yield precious minerals such as gold, platinum and rare-Earth metals.

BBC: New venture 'to mine asteroids'