- Mira (stars.astro.illinois.edu)
MIRA (Omicron Ceti). Mira, its very name telling us that we should take strong notice, Mira “the amazing one,” the word coming from the same root as “miracle,” Mira the only proper-named star in the sky that for a time is too faint to be seen with the naked eye.
- Diatomaceous earth (Wikipedia)
Diatomaceous earth (/ˌdaɪ.ətəˈmeɪʃəs/ DY-ə-tə-MAY-shəs), also known as diatomite (/daɪˈætəmaɪt/ dy-AT-ə-myte), celite, or kieselguhr, is a naturally occurring, soft, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging from more than 3 mm to less than 1 μm, but typically 10 to 200 μm. Depending on the granularity, this powder can have an abrasive feel, similar to pumice powder, and has a low density as a result of its high porosity. The typical chemical composition of oven-dried diatomaceous earth is 80–90% silica, with 2–4% alumina (attributed mostly to clay minerals), and 0.5–2% iron oxide.