There are two minerals commonly called jade: jadeite & nephrite. Both are calcium magnesium silicate hydroxides, but jadeite is made of interlocking, granular crystals, whereas nephrite crystals are fibrous, making it tougher than steel and great for carving. Nephrite is more common than jadeite. The name is derived from the Latin nephrus, meaning “kidney,” alluding to its use in Europe to treat kidney disease. Large deposits of nephrite are found in Alaska, British Columbia, Siberia, China, and California. It is used metaphysically for health, wealth, and fidelity.