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
Shades of cyan one of the Sharpie (marker) permanent markers but not as bright on the marker. However, there is no mechanism for showing fluorescence on a computer screen. Aquamarine is a shade of cyan toned towards green. It is named after the mineral aquamarine, a gemstone mainly found in granite rocks. The first recorded use of "aquamarine" as a color name in English was in 1598. AuroMetalSaurus is dark grayish shade of cyan. Blue-green has been a Crayola color since 1930. Displayed at right is the color Caribbean Current. At right is displayed the color celeste. Bleu celeste ("sky blue") is a