Æther is measured in drams, which are also the unit of currency in many lands where the substance is harvested and used in various machinations. The units are as follows. Four drams (4ᵭ) to the nip. 3 nips (3ꬻ) to the gil (1ꬶ). 1ꬶ of aether is about a teacupfull liquid radiant. Dram coins frequently (depending on the local culture) have an aether crystal set in the coin itself, whereas larger denominations of coins are theoretically exchangeable for aether. Seximal and duodecimal denominations are normal for other currencies.
Of course, a 1 gil aether stone may be worth considerably more or considerably less depending on the intensity and nature of the radiance stored therein and on market forces.