chalcedony

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Cathedrale St.Jean in Lyon, France has a 14th-century astronomical clock that shows religious feast days till the year 2019; Perpetual Calendar

Ten Days That Vanished: The Switch to the Gregorian Calendar

Amendments 1-10 to the Constitution of the United States constitute what is known as the Bill of Rights on an American flag.

What Is the Emoluments Clause?

Figure 13: A Maxim machine gun, belt-fed and water-cooled, operated by German infantrymen, World War I.

7 Deadliest Weapons in History

Drinking water is poured into a glass.

Water Fluoridation: Just the Facts

King Cobra snake in Malaysia. (reptile)

9 of the World’s Deadliest Snakes

Poker game. Card game. Royal Flush in poker. Hearts suit gambling

Poker Hands Ranked

Portrait of a mountain gorilla at a short distance. gorilla close up portrait.The mountain gorilla (Gorilla beringei beringei)

Falling Stars: 10 of the Most Famous Endangered Species

chalcedony: Facts & Related Content

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Also Known As	calcedony

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sard and sardonyx agate onyx sardonyx carnelian bloodstone chrysoprase plasma prase moss agate garnet jade opal topaz turquoise jasper jadeite zircon amethyst kyanite

Quiz

Basalt sample returned by Apollo 15, from near a long sinous lunar valley called Hadley Rille. Measured at 3.3 years old.

(Bed) Rocks and (Flint) Stones