Boulder Rocks

We are offering rock with grain size of usually no less than 30 centimetres (1 ft) diameter. While a boulder may be small enough to move or roll manually, others are extremely massive. In common usage, a boulder is too large for a person to move. Smaller boulders are usually just called rocks or stones. rock with grain size of usually no less than 30 centimetres (1 ft) diameter. While a boulder may be small enough to move or roll manually, others are extremely massive. In common usage, a boulder is too large for a person to move. Smaller boulders are usually just called rocks or stones.