Well, I’ve certainly been one of those who has noticed the way that Manhattan sidewalks often appear sprinkled with glitter. Sometimes sparkling like a thousand tiny flashbulbs, I’ve been known to think of it as my paparazzi.
Turns out that it’s due to the Manhattan schist, the native bedrock which has flecks of mica in it, which has been mixed into the cement that makes up many of the island’s sidewalks.