Weight of 1m by 1m by 1m rubber?

It depends on the density of rubber. Different kind of rubber have different density so different weights. weight = volume X Density in your case the volume is 1cuM. Natural rubber - 920 Kg/cu M Neoprene Rubber - 1230 kg/ cu M Silicone Rubber - 1150 kg/cu M EPDM Rubber - 860 kg/cu M Ramki- India