-Weight: 21.45 grams per cubic centimetre -Melting Point: 1,786ºC (3,223ºF) -Refining: It takes eight weeks to make an ingot from the ore -Production: Each year approximately 88 tons of platinum are made into jewellery -Properties: Catalyst, hypoallergenic, resistant to heat and acids -Platinum group metals: Ruthenium, Palladium, Rhodium, Iridium, Osmium -Measuring purity: 1,000 parts = 100% platinum
Purity levels and marks
Country
Purity levels
Stamp
UK
China
950
900, 950
950
Pt
Germany
850,950, 999
Pt950, pt999
India
950
Pt950 (by an assay office)
Italy
950 up (but EEC is 850, 900, 950 and up)
Pt950 and sometimes the word platinum (no assay office, done by manufacturer)
Japan
850, 900, 950, 999. 1000
Pt then purity level
US
850, 900, 950+ are the most common purity levels
Platinum, pt, plat (no standard)
Platinum alloys for jewellery
Alloy
Chemical symbol
Recommended usage
Platinum - Copper
Pt - Cu
Medium hard for general purpose
Platinum - Palladium
Pt - Pd
Easier to use for delicate settings
Platinum - Cobalt
Pt - Co
For casting, wedding bands and fine wire
Platinum - Tungsten
Pt - W
Extra hard, for safety catches, pins, springs, watch backs
Platinum - Palladium - Copper
Pt - Pd - Cu
Copper for chain making and general purpose
Platinum - Ruthenium
Pt - Ru
Casting, machining and fabricating
Platinum - Iridium
Pt - Ir
Fabricating, casting (950 Pt - Ir too soft for casting )
