The three types of rocks igneous, sedimentary, and metamorphic are all subject to processes that change one rock type into another. The images below show several types of rocks undergoing these processes.
Lime is a soil amendment made by grinding limestone, a naturally occurring type of rock that is very high in calcium. Two types of lime are commonly used in lawns and gardens, agricultural lime and dolomitic lime. Agricultural lime, also sold as garden lime, is made from calcium carbonate.
Even when properly mixed with the soil, lime will have little effect on pH if the soil is dry. Moisture is essential for the lime-soil reaction to occur. In the case of lawns, it can only be surface applied and watered into the soil. Wood Ashes: Wood ashes can be used to raise the soil pH.