How do you crack marbles?

Answer 1

If you are referring to glass marbles then just heat in an oven and plunge into water but since this is a geology section you might mean "crack Marble" as in preparation for mining. To do that the old way was to drill a number of holes and drive wooden pegs in and add water to make them swell and crack marble. That was the way from Egyptian times to the 1800's. Blasting will remove chunks if gravel is wanted or blocky chunks but if you want a piece for statuary or for building stone it is usually cut using a wire saw, reciprocating saw, high temperature torch (Kerosene + Oxygen) or a giant chainsaw up to 40 feet long.

Answer 2

To crack marbles, you can wrap them in a cloth or place them in a sock and hit them with a hammer or mallet until they break. Another method is to heat the marble with a torch or in the oven and then drop it in cold water, causing it to crack. Remember to wear safety goggles and gloves when cracking marbles.