noun. A gemstone associated with a particular month and customarily worn by persons born during that month.

noun. Any of twelve gemstones traditionally associated with the month of one's birth

noun. Any of a similar list of less costly substitutes

"In fact, March and April aren't that exciting either so those could be two weeks, too, except that it greatly shortens the chances that your birthstone will be a diamond."

GP  boomerang  civitatem  dulcis  epoch-marking