YOU DECIDE TO GO OUTSIDE
You shove the gem into your pocket and run out the front door of your house. Outside is a nightmare come to life.
It looks like everyone in the city is outside in the street, running and screaming.
You are nearly struck by a speeding car as it veers off the road onto your lawn to avoid hitting a child running across the street and yelling for her mother.
Your car keys are in your pocket with the crystal, probably scratching it up, whatever it is.
Your car is in the driveway, and you think it has about half a tank of gas.
You notice that traffic is highly chaotic, but trying to run a mile to the edge of the city could take longer than normal, and you might not have the stamina to get free of the blast zone in time.