spinel

noun

1. (countable, uncountable)Any of several hard minerals of cubic symmetry that are mixed oxides of magnesium and aluminium and are used as gemstones of various colours.

   “Although there are dozens of different types of gems, among the best known and most important are […] . (Common gem materials not addressed in this article include amber, amethyst, chalcedony, garnet, lazurite, malachite, opals, peridot, rhodonite, spinel, tourmaline, turquoise and zircon.)”

2. (countable, uncountable)Any crystalline material, not necessarily an oxide, that possesses the same crystal structure as this mineral.
3. (countable, obsolete, uncountable)Spindle; the amount of yarn that fits on a spindle.

   “[…] raised the price of that staple of yarn (of one Spinel in the pound weight) from 23d. to 26d. per Spinel.”

   “339, 612 yards of dimities, muslinets, jaconets, and booked muslins, from rod. to 20s. per yard, and, 4000. spinels of thread and yarn, were bleached by him in 1791, and 45 people were employed in the work.”

   “... that is fit for any hundred of the reed; and like- wise the number of right telled yarn in spinels, slips, and cuts, that will be sufficient to make any number of ells from 1 to 60, subject, and merely consisted of tables or ready[…]”