950 Platinum — What This Hallmark Means

A "950" mark on platinum jewelry means the piece is made from an alloy containing 95% pure platinum and 5% other metals, typically ruthenium, iridium, or cobalt. This is the most widely used platinum purity for fine jewelry and is the standard in most major markets. Platinum's natural white color, extreme durability, and hypoallergenic properties make it one of the most desirable precious metals for jewelry.

Platinum is approximately 30 times rarer than gold and is significantly denser — a platinum ring will feel noticeably heavier than the same ring made in gold. Unlike white gold, platinum is naturally white and never needs rhodium plating. Over time, platinum develops a distinctive patina — a subtle matte finish that many owners find attractive, though it can be polished back to a high shine.

The 5% alloying metals in 950 platinum serve important purposes. Ruthenium and iridium increase hardness, making the platinum more resistant to wear. Cobalt improves the alloy's castability, which is important for manufacturing. Despite these additions, 950 platinum remains hypoallergenic and biocompatible, making it safe for people with metal sensitivities.

The 950 platinum mark is typically found inside ring bands, on clasps, and on other inconspicuous areas of the jewelry. It is often accompanied by "PLAT," "PT," "Pt950," or "PLATINUM." On high-end watch cases, the mark appears on the case back.

In many countries, platinum jewelry must be hallmarked by an assay office before it can be sold. UK platinum carries an orb symbol as part of its hallmark, while other countries have their own platinum-specific assay marks.

Common variations include "950," "Pt950," "PLAT," "PT," ".950," and "PLATINUM." In the UK hallmarking system, platinum is identified by an orb symbol alongside the 950 fineness mark. Japanese platinum often shows "Pt950" or simply "Pt."

Some older pieces may carry "IRID PLAT" indicating an iridium-platinum alloy, or "PLAT/IRID" with similar meaning. Vintage American platinum jewelry sometimes shows just "PLAT" without a numeric purity mark, which under US law indicates at least 950 parts per thousand platinum.

A major misconception is that platinum doesn't scratch. Platinum does scratch — possibly even more visibly than gold in the short term. However, when platinum scratches, the metal is displaced rather than lost, meaning the piece retains its weight and mass over time. Gold, by contrast, actually loses tiny amounts of metal with each scratch.

Another common myth is that platinum and white gold are essentially the same. They are fundamentally different metals. Platinum is naturally white, denser, more durable in the long run, hypoallergenic, and doesn't require plating. White gold is a gold alloy that often contains nickel and requires rhodium plating to maintain its white appearance.

If your jewelry is marked 950 Pt, you have a premium piece made from one of the world's most precious metals. Platinum requires minimal maintenance — clean it with warm soapy water and a soft brush. The patina that develops over time can be polished away by a jeweler if you prefer a high shine.

Store platinum jewelry separately from gold and silver, as platinum's density and hardness can scratch softer metals. For insurance and resale purposes, have your platinum jewelry appraised by a certified gemologist who can verify both the metal and any gemstones.