Since we have no natural rocks, and buying large rocks is very expensive, we decided to make our own We started with sand, wet and roughly shaped. We then covered the sand with dry sandmix readymix cement, about an inch thick. Sprinkled with fine mist until wet. After 2 days, wet and add 1 iinch of sandmix, wet, another inch let harden for a couple of days. Obtain concrete dye, we used mixture of Terra Cotta and Buff with a little black to darken. Mix this wet and pour it on with a shovel. Avoid smoothing as this will show later. When it is firm to the touch, use black paint and a large brush and sling splatters onto the mix. Bumps and so forth help the look.
These pictures are our first try in 1998.