Pearls are the most valuable of all organic gemstones. Prized for 6000 years. Pearls chemical makeup varies by region & environmental factors but the basic formula is irritant is coated (mother of pearl)^
Venus - one day is longer than its entire year. It takes Venus 243 Earth days to completely rotate on its axis, but just 225 days to orbit the sun. Venus is one of two planets that rotates in reverse, called retrograde motion.
Hubble's Sharpest View of the Orion Nebula: Thousands of stars are forming in the cloud of gas and dust known as the Orion nebula. More than stars of various sizes appear in this image. Some of them have never been seen in visible light.