For the purpose of calculating the tax under Code Section 48-15-6, a quantity of marijuana or other controlled substance in the person's possession shall be measured by the weight of the substance whether pure or impure or dilute, or by dosage units when the substance is not sold by weight. A quantity of a controlled substance is dilute if it consists of a detectable quantity of pure controlled substance and any excipients or fillers.
(Code 1981, §48-15-5, enacted by Ga. L. 1990, p. 1231, § 1.)