Precious Gems & Minerals

Diamond is the hardest natural substance, scoring 10 on the Mohs hardness scale. It is made of pure carbon atoms arranged in a crystal structure.

The ruby is the birthstone for July. Rubies are a variety of the mineral corundum and get their red color from the element chromium.

Emeralds are green gemstones, a variety of the mineral beryl. Their green color comes from trace amounts of chromium and sometimes vanadium.

Pearls are produced by oysters and some other mollusks. When an irritant enters the shell, the animal coats it with layers of nacre (mother-of-pearl), gradually forming a pearl.

The ruby has been called the 'king of gems' throughout history. In ancient India, rubies were called 'ratnaraj,' which translates to 'king of precious stones.'

Ruby is a variety of the mineral corundum (aluminum oxide). Sapphire is also a variety of corundum — the only difference is the trace elements that give them their colors.

Opals are famous for their play of color, caused by the diffraction of light through tiny silica spheres within the stone. Australian opals account for about 95% of the world's supply.

Amethyst's purple color comes from iron impurities within the quartz crystal, combined with irradiation. Amethyst is a variety of quartz and was once considered as valuable as diamonds.

Russia is the world's largest producer of diamonds by volume, primarily from mines in Siberia. The Mirny Mine in Yakutia is one of the largest open-pit diamond mines in the world.

Feldspar is the most abundant mineral group in the Earth's crust, making up about 60% of it. Quartz is the second most abundant mineral in the continental crust.

The Hope Diamond is a 45.52-carat deep-blue diamond housed in the Smithsonian National Museum of Natural History. It is famous for its supposedly cursed history and its rare blue color caused by trace amounts of boron.

Lapis lazuli is a deep-blue metamorphic rock primarily composed of the mineral lazurite. It has been prized since antiquity and was ground into powder to make the pigment ultramarine, used in Renaissance paintings.

Alexandrite is famous for its dramatic color change: green in daylight and red under incandescent light. It was first discovered in Russia's Ural Mountains in the 1830s and named after Tsar Alexander II.

Talc is rated 1 on the Mohs hardness scale, making it the softest known mineral. It can be scratched with a fingernail. Talc is commonly used in talcum powder.

Tanzanite is found exclusively in the Mererani Hills of northern Tanzania, near Mount Kilimanjaro. It was discovered in 1967 and named by Tiffany & Co. after its country of origin.