Business and Professions Code section 22128
(a)
An article consisting of at least 985/1000ths parts of platinum, iridium, palladium, ruthenium, rhodium, or osmium, where solder is not used and at least 950/1000ths parts of said metal or metals where solder is used, may be marked “platinum”; provided, that the total of the aforementioned metals other than pure platinum shall amount to no more than 50/1000ths parts of the contents of the entire article.(b)
An article consisting of at least 985/1000ths parts of platinum, iridium, palladium, ruthenium, or osmium, where solder is not used and at least 950/1000ths parts of the said metal or metals where solder is used; and provided further, that at least 750/1000ths parts of said article are pure platinum, may be marked “platinum”; provided immediately preceding the mark “platinum” there is marked the name or abbreviation of either iridium, palladium, ruthenium, rhodium, or osmium, whichever of said metals predominates; and provided further, that such predominating other metal must be more than 50/1000ths parts of the entire article.(c)
An article consisting of at least 985/1000ths parts of platinum, iridium, palladium, ruthenium, rhodium, or osmium, where solder is not used and at least 950/1000ths parts of said metals where solder is used; provided, more than 500/1000ths parts of said article consists of pure platinum, may be marked with the word “platinum”; provided, that said word is immediately preceded by a decimal fraction in one-thousandths showing the platinum content of the entire article; and further provided, that said mark “platinum” be followed by the name or abbreviation as herein allowed, of such one or more of the following metals, to wit: iridium, palladium, ruthenium, rhodium, or osmium, that may be present in the article in quantity of more than 50/1000ths parts of the entire article. The name of such other metal or metals other than platinum, however, shall each be immediately preceded by a decimal fraction in one-thousandths showing the content of such other metal or metals in proportion to the entire article, as for example, 600 plat., 350 pall., or 500 plat., 200 pall., 150 ruth., 100 rhod.(d)
An article consisting of 950/1000ths parts of the following metals: Platinum, iridium, palladium, ruthenium, rhodium, or osmium with less than 500/1000ths parts of the entire article consisting of pure platinum, may be marked with the name iridium, palladium, ruthenium, rhodium, or osmium, whichever predominates in the said article, but in no event with the mark “platinum”; provided, however, that the quantity of such metal other than platinum so marked, must be marked in decimal thousandths; and provided further, that the name of such metal other than platinum so used must be spelled out in full irrespective of any other provisions of this article to the contrary.(e)
An article composed of platinum and gold which resembles, appears or purports to be platinum, may be marked with a carat mark and the platinum mark; provided:(f)
An article composed of platinum and any other material or metal not resembling, appearing or purporting to be platinum, may be marked with the word “platinum”; provided, all parts or portions of such article resembling or appearing or purporting to be platinum, or reasonably purporting to be described as platinum by said quality mark, shall be at least 985/1000ths parts pure platinum.
Source:
Section 22128, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=BPC§ionNum=22128.
(accessed May 4, 2025).