Carnelian is a translucent red or orange variety of chalcedony, sometimes banded red and orange like an agate. Once believed to benefit the wearer's health and love life. Most carnelian comes from Brazil, India, Siberia, and Germany.
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.
Moonstone is a variety of orthoclase, a feldspar. It often has a sky blue opalescent sheen, also called schiller or fire, making the stone look as if it is glowing. The sheen is created by thin layering of orthoclase with another mineral, albite. Moonstone was used in jewelry from 100 AD in Rome and even earlier in Asia.
Derived from "tapaz," the Sanskrit word for fire, topaz is one of the most brilliant cut gemstones in existence. Topaz comes in a variety of colors from yellow to blue, and deeper blues and pinks are often created by heat-treating stones. Brazil is the world's top exporter of topaz.