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.
Researchers at Iowa State University have found that ground eggshells are a good source of lime for the garden. Others at the University of Florida claim that eggshells raise soil pH and promote early root growth. Instead of spending money at the nursery, save those eggshells and make some homemade plant fertilizer. Save your eggshells in a brown paper bag. The eggshells should be dry prior to crushing them. To dry them quickly, place them, in a shallow pan, in the oven. Turn the heat to its lowest setting and allow the eggshells to remain in the oven until they are beginning to turn brown.