Short Answer
Complete Explanation
Pt950 is a hallmark used in the jewellery industry to denote a platinum alloy that contains 95 % pure platinum by weight. The remaining 5 % typically consists of metals such as iridium, ruthenium, palladium, or copper, which are added to increase hardness and durability while maintaining the desirable properties of platinum, such as its white‑luster and resistance to tarnish. The stamp is applied by the manufacturer or an authorized assay office and conforms to standards set by organisations such as the International Platinum Group Metals Association (IPGMA) and the ISO 2409 jewellery marking system.
- Purity Level:
95 % platinum, 5 % alloying metals. - Common Alloying Metals:
Iridium, ruthenium, palladium, copper, or a combination thereof. - Typical Hallmark Appearance:
Engraved or stamped as “PT950”, often accompanied by a maker’s mark and a country code. - Physical Characteristics:
Higher density (≈21.4 g/cm³) than gold or silver, retains a bright white colour without rhodium plating. - Durability:
Harder than pure platinum (PT999) but softer than many white gold alloys; resistant to scratching but can show wear over time. - Care Recommendations:
Clean with mild soap and warm water; avoid harsh chemicals; polish with a soft cloth or professional jeweller when needed.
Common Misconceptions
Pt950 is 100 % pure platinum.
The “950” indicates 95 % platinum; the remaining 5 % are other metals that improve strength.
Pt950 cannot be scratched or dented.
While more resistant than softer alloys, Pt950 can still show minor scratches with everyday wear.
All platinum jewellery is stamped PT950.
Some pieces use PT900 (90 % platinum) or higher purity PT999; the stamp always specifies the exact purity.
FAQ
Is PT950 the same as 950 platinum?
Yes. The abbreviation PT950 or 950 % platinum both indicate an alloy containing 95 % pure platinum and 5 % other metals.
Can PT950 be re‑plated with rhodium?
Rhodium plating is unnecessary for PT950 because it already has a naturally white colour, but some owners choose to plate it for additional shine or to mask surface wear.
How does PT950 compare to 14‑karat white gold?
PT950 is denser, more hypoallergenic, and does not require rhodium plating to achieve a white hue, whereas 14‑K white gold is an alloy of gold with nickel or palladium and typically needs plating.
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