Gemstone usually found in. For example, diamonds, which have a cubic crystal system, are often found as octahedrons. Gemstones are classified into different "groups", "species", and "varieties". For example, ruby is the red variety of the species corundum, while any other color of corundum is considered sapphire. Other examples are the emerald (green), aquamarine (blue), red beryl (red), goshenite (colorless), heliodor (yellow) and morganite (pink), which are all varieties of the mineral species beryl. Gems are characterized in terms of refractive index, dispersion, specific gravity, hardness, cleavage, fracture and luster. They may exhibit pleochroism or double refraction. They may have luminescence
USS Aquamarine (PYc-7) for disposal. She was sold to Colonel E. M. Grimm of Columbus, Ohio, in 1947, and her name changed back to "Seawolf". She was sold in 1954 to Ennolls A. Stephens of Irvington, Virginia, owner of The Tides Inn, Irvington, and renamed "Miss Ann". In 2008, "Miss Ann" was sold to private interests who placed her in Charter Service on the Potomac River. In 2014, she is located at the Colonial Beach Yacht Club in Colonial Beach, Virginia. USS Aquamarine (PYc-7) USS "Aquamarine" (PYc-7) was a patrol boat in the United States Navy during World War II. Later known as