Boulders usualy range from 2 to 5 feet. A 3'x3'x2' boulder typically weighs 1 ton or 2000 Lbs.
A 2' diameter boulder weighs about 750 Lbs. Figure half that weight for lava boulders.
Note: Coverage for Granite boulders= 168 lb. per cu. ft.
*PICTURES MAY NOT PORTRAY PROPER COLOR OR SIZE.
ALWAYS LOOK AT MATERIAL IN PERSON BEFORE PURCHASING