Silver – Pure Silver has a specific gravity of 10.50. Sterling Silver has a specific gravity of 10.10. Sterling Silver is made up of 92.50 % pure silver and 7.5% of other alloys (usually copper). Silver has a melting point of 802 degrees Celsius. This makes it easy to work with, as it is relatively soft.
Gold – Pure Gold (24ct gold) has a specific gravity of 19.30 and a melting point of 1,064 degrees Celsius.
18ct Yellow Gold – 75% pure gold (750 stamp)- usually 25% silver. Specific Gravity 16.04
18ct Rose Gold – 75% pure gold (750 stamp) – usually 25% copper. Specific Gravity 15.45
18ct White Gold – 75% pure gold (750 stamp)- usually 25% palladium or Nickel. Specific Gravity 16.59
9ct Gold – 37.5% pure gold (375 stamp) – depending on the colour a greater (62.5% of the above), Specific Gravity of 11.64
Platinum – Platinum has a specific gravity of 21.50 and a melting point of 1,768 degrees Celsius. Platinum Jewellery is usually stamped 950 (95% pure platinum) and usually Palladium
The 2 used in Jewellery finishing are
Palladium – is used in white gold and platinum. In White gold, it helps tone down the yellow gold and increases the white and then Jewellery is plated with rhodium. Platinum is used to make platinum more malleable.
Rhodium – Often used as a plating solution on 18ct white gold gold, to give it a brighter white finish. As white gold is not naturally occurring like Platinum or Palladium, it needs plating to enhance it. Rhodium plating does react with its environment and will fade away over time. Especially noticeable on the underneath of rings were picking up bags, opening doors eroding the plating over time.
We get asked the question all the time – and I always recommend Platinum if you want a white metal and if you do want a mix of yellow and for example white metal, again – platinum gives you the extra strength.
We charge the same price for 18ct gold (yellow or white) as we do for platinum. So the choice is completely yours on what your preference is.