Gemstones associated with metamorphic rock include beryl, jade, lapis lazuli, turquoise, spinel, ruby, sapphire and zircon. Rocks and minerals are in a constant state of change, which is referred to as the rock cycle. Igneous rock can change into sedimentary or metamorphic rock.
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.
Slaked lime is used to make lime mortar. The mortar is made by mixing sand with slaked lime at the proportion of 1 part lime to 5 parts sand. There are two types of lime used in lime mortars, one that sets and hardens by the reaction with the air (non-hydraulic) and one which sets by reaction to the water (hydraulic).