01Decisive
Confirm the weight matches the volume
PT950's density of about 21 is unmatched by any plausible substitute at jewellery prices. Compare against a known white gold piece of similar size: the platinum should be roughly a third heavier.
PLAT / 950 · Lovenhall Ring
The PT950 Mark
95% platinum, the modern international standard. The mark most new platinum carries.
The international marks for platinum, standardised at 950 for unqualified use4 references
PT950 is 95 percent platinum with the balance usually ruthenium, iridium or cobalt, and it is the standard for modern platinum jewellery worldwide. The alloying metal is chosen for working properties: cobalt alloys cast well and take a high polish, ruthenium alloys are harder, iridium alloys are traditional and very ductile.
The 5 percent matters less than it would in gold because all the common alloying metals are themselves platinum-group and share platinum's whiteness and inertness. That is why platinum needs no plating at any fineness.
In the United Kingdom platinum has been subject to compulsory hallmarking since 1975, so a British piece should carry a sponsor's mark, the 950 fineness figure and an assay office mark, often with the platinum orb symbol. Below 0.5 grams the exemption applies.
References and sizes
PT950 · 950 · 950 PLAT · Pt 950
Establish which of these you are holding before judging it. A genuine piece read against another reference's rules will look wrong when it is not.
Model-specific checks
What decides a PT950
These apply to this model and not to the rest of PLAT / 950. Work them alongside the maker's general checks, not instead of them.
02Strong
Look for the British platinum orb on UK work
Platinum has been compulsorily hallmarked in the UK since 1975. A British piece above 0.5 grams should carry a sponsor's mark, 950, and an assay office mark, often with the orb symbol.
The market
What a PT950 does on the secondary market
Priced by weight and workmanship. Denser than gold, so a comparable ring uses more metal.
An orientation for honest, unrestored condition — never an appraisal, and never a quotation.
All the PLAT / 950 checks
Free tools of the room
Lovenhall RingRead the whole piece
The mark tells you what the metal claims to be. The instrument reads the setting and the stones together and gives a range to orient you — before anyone charges you for an appraisal.
Free on iPhone & iPad. An estimate, never an appraisal.
Or write to the house