Platinum jewelry is very rare; in fact, 30 times more so than gold. Our platinum is 95% pure (5% iridium, palladium, ruthenium, and other alloys), and its purity makes it naturally hypoallergenic, ideal for those with sensitive skin issues.
Most high quality silver items are stamped with a "fineness" or "quality" mark. This mark designates the precious metal content of the jewelry, and under federal law, must be accompanied by a maker's mark or registered trademark.
It's easy. Simply soak platinum in a mild solution of warm soapy water, and then gently scrub it with a soft-bristled brush.