Carat & Hallmarking –
The carat of a piece of metal tells you how much gold there is in the metal in proportion to the other metals that it has been alloyed with. 18ct gold contains 75% gold, 14ct is 58.5% gold and 9ct is 37.5% gold.
All of my gold jewellery and some larger silver pieces will be hallmarked. It is the law to hallmark gold jewellery that weighs over 1gram & silver jewellery that weighs over 7.78grams. I am registered with Sheffield Assay Office whose mark is the Rose:
The hallmarking standards are:
Sterling Silver ~ 925
9ct Gold ~ 375
14ct Gold ~ 585
18ct Gold ~ 750
If a piece of jewellery is ‘mixed metal’ it will be hallmarked with the least precious metal, for example, a piece that is part silver & part gold would be hallmarked as 925 with a ‘part mark’ for the gold.
Gold: Hardness vs. Durability –
Pure gold is very soft and so it is alloyed with other metals to add strength, hardness & durability. 9ct gold tends to be harder, i.e. more resistant to scuffs & scratches, as there is a higher proportion of other tougher metals, such as copper and silver. However – as pure gold doesn’t tarnish – 18ct is considered more durable as it has less alloyed metals, such as silver, which tarnish over time.
18ct white gold is primarily alloyed with palladium instead of silver which adds hardness as well, making 18ct generally the preferred option for wedding and engagement rings as it has strength and durability. However we are talking about durability over multiple lifetimes and so 9ct and 14ct can offer an affordable option that will look good for many years.
Yellow gold is normally alloyed with silver, copper and zinc to strengthen the metal & enhance the colour. It has warm tones and can provide beautiful contrast with coloured precious stones and other metals.
It is worth noting that different manufacturers use different ‘recipes’ when forging gold. The metal I use is 100% recycled and tends to be a little redder than other yellow gold I’ve seen – I love it as it’s softer rather than ‘brassy’. 18ct yellow gold will be more yellow than 9ct as it has more gold in it.
White gold is yellow gold that has been alloyed with either silver for 9ct or palladium for 18ct to produce the white/grey colour. I only use palladium white gold & never rhodium plated as it wears off over & time & requires re-plating. Rhodium-plated white gold tends to be whiter, but personally I love the darker grey colour of palladium white gold which is quite similar in colour to platinum.