Block: Miscellaneous Mathematical Symbols-B

Range U+2980 - U+29FF
Official Chart http://www.unicode.org/charts/PDF/U2980.pdf
Wikipedia This is a list of symbols used in all branches of mathematics to express a formula or to represent a constant. A mathematical concept is independent of the symbol chosen to represent it. For many of the symbols below, the symbol is usually synonymous with the corresponding concept (ultimately an arbitrary choice made as a result of the cumulative history of mathematics), but in some situations, a different convention may be used.
https://en.wikipedia.org/wiki/Miscellaneous_Mathematical_Symbols-B
Characters
⦿ ⧿