Overall Dimension: 1.15 x 0.25 x 0.2 inches; Bail Dimension: 0.15 inches. SKU: p31008; Weight: 3.5g; Stone: 5 genuine iolite; Material: Genuine Sterling Silver (925 silver, 92.5% silver content); Stamp: 925; Iolite is the deep blue gem variety of the silicate mineral cordierite, named for French geologist Pierre Cordier. Iolite is found on Garnet Island in Canada and in South Asia and South Africa. Leif Eriksson and other Viking explorers are said to have used thin slices of iolite to navigate during voyages, taking advantage of its prismatic properties to polarize sunlight.