Creatinine is a normal waste product produced by muscle metabolism. When your kidneys are functioning normally, they filter creatinine and other waste products out of your blood and send them out of the body through urine. A creatinine urine test measures the amount of creatinine in your urine and can help your doctor evaluate how well your kidneys filter waste. This is useful in diagnosing or ruling out kidney diseases and some other conditions.
These terms are based on old traditions from the west. These days, all gemstones are considered precious since they are all rare and there is a limited supply of them. The traditional list of gemstones that are considered precious stones are: Diamond.
An introduction to crystal chemistry helps in understanding what gems are made of and how this affects gemstone environments and associations. Most gemstones are minerals, inorganic crystal treasures found in the natural world. Some gemstones are not minerals but are organically derived, such as amber and jet. Inorganic gems are crystalline, while organic gems are non-crystalline so described as amorphous, or without the crystalline form.