Sunstone

Sunstone is one of those gemstones with a genuinely fascinating backstory. It's a type of feldspar that exhibits a brilliant spangled appearance called schiller — caused by light reflecting off internal inclusions of red minerals — giving it a warm, glittery glow that looks like sunlight captured in stone. Here's the history that really gets us: a theory exists that ancient Viking seafarers used sunstone as a polarizing navigation instrument, and a stone found in 2013 in the wreck of a 16th-century warship may be evidence of exactly that.