- Star Tales - Perseus (ianridpath.com)
Perseus (Περσεύς in Greek) is one of the most famous Greek heroes. The characters in his story are represented by six constellations that occupy a substantial part of the sky. The constellation depicting Perseus lies in a prominent part of the Milky Way, which is perhaps why Aratus termed him ‘dust-stained’.
- Silicon dioxide (Wikipedia)
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula SiO2, commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant families of materials, existing as a compound of several minerals and as a synthetic product. Examples include fused quartz, fumed silica, opal, and aerogels. It is used in structural materials, microelectronics, and as components in the food and pharmaceutical industries. All forms are white or colorless, although impure samples can be colored.