No.109 | Signature Solitaire | Australian Blue Sapphire

The difference between 9ct, 14ct and 18ct gold is the precious metal content. 9ct gold contains 37.5% pure gold, 14ct contains 58.5% pure gold and 18ct gold contains 75% pure gold. The remainder is a mix of various metals, depending on whether it is a yellow, rose or white gold piece.

In general, 18ct gold is the longer lasting, more durable choice, however 9ct gold can still be a great option for some Jewellery pieces. 9ct gold is commonly used for fine pieces of jewellery that are typically designed for casual wear. Our seasonal collection fashion pieces, or statement pieces are typically crafted in 9ct gold. The reason for this is that these are generally our finest pieces, and where 18ct is flexible, 9ct gold is more rigid and holds its shape better as it has the lowest pure gold content – making it great for casual wear while also bringing it into a more accessible price point.  At NMJ, we always recommend 18ct gold for all precious pieces such as engagement rings and wedding bands.

Put simply, the higher the gold content, the richer the colour and warmer the tone, particularly for yellow and rose gold. However, only when side-by-side are these differences really noticeable to the eye, and they are generally quite subtle so don’t affect the overall aesthetic of your piece of jewellery. The thinner or smaller your piece, the less noticeable the colour difference will be.

As an industry standard, most white gold is rhodium plated. This means you’re not actually seeing the natural colour of the metal as it is plated in a thin layer of rhodium, which is a naturally white metal, so that the stunning bright silver-colour appears consistent no matter the carat. This finish is generally reapplied annually when rings are serviced to maintain the colour.  

If you’re opting for an un-plated white gold, the natural colour of the metal in 9ct is slightly darker than sterling silver. You will find that the 9ct looks silvery, and then the higher the carat the darker the grey tone becomes, resulting in more of a steely grey with a slight warmth, making it a popular choice for mens wedding rings.

9ct rose gold is a soft pink, while 14ct and 18ct are a much warmer, peach-toned colour. Our 18 carat rose gold alloy is always popular for its soft warmth and lack of coppery undertone. 

9ct yellow gold appears as a subtle, pale yellow while higher carats, such as 18ct in particular, present a richer, more vibrant golden tone. As a 9 carat alloy is more diluted with other metals, there can be some minor colour evolution or tarnishing over time, whereas 18 carat has a more stable finish. 

The carat finish can be identified by a small stamp (hallmark) located on the gold, typically in a discreet spot such as the inside of a band, the clasp of a necklace or bracelet or the post or butterfly of your earrings.

9ct - ‘9ct’, ‘9k’ or ‘375’

14ct – ‘14ct’, ‘14k’ or ‘585’

18ct – ‘18ct’, ‘18k’ or ‘750’