Anywhere from nothing to about 41%. On the Axiom Diamond Cross Pendant, platinum and 18K gold cost exactly the same. On the Aura Linear Diamond Ear Cuff, moving from 9K to 18K adds 41%. And platinum is not automatically the top of the ladder: on the Meridian bracelet it sits below 18K white gold.
Why can nobody quote you a single metal premium?
Most people configuring a piece carry two assumptions into it. The first is that metals form a tidy ladder: 9K cheapest, then 14K, then 18K, with platinum capping it. The second is that each step is worth some rough percentage, maybe 20% or 30%, that holds across a catalogue.
Neither survives contact with live prices. Carat Club Co. prices from what the materials and the making actually cost, rather than applying a fixed markup on top of a metal choice, which is the same reasoning behind why lab-grown diamonds cost so much less than mined stones. The consequence is that the metal premium is a different number on every product, and sometimes a different number on every variant of the same product.
Is platinum always the most expensive metal?
No. Here is the Meridian Men's Emerald-Cut Tennis Bracelet at 17cm. Every stone in it is a 0.25ct emerald cut, so carat weight is fixed and metal is the only variable in play.
| Metal (17cm) | Price | Position on the ladder |
|---|---|---|
| 9K White Gold | HK$34,000 | Lowest |
| 14K White Gold | HK$39,500 | Second |
| PT950 Platinum | HK$41,500 | Third, below 18K |
| 18K White Gold | HK$44,000 | Highest |
9K to 18K is HK$10,000, a 29% step. But PT950 platinum lands HK$2,500 below 18K white gold, and it undercuts 18K at every length offered, not just at 17cm.
Carat Club Co. states the reason on the product page: platinum metal currently costs less than 18K gold, and prices follow real material cost instead of a fixed markup. That relationship reflects pricing at the time of writing and can move. If you want the two compared on how they look and wear rather than what they cost, read Platinum or 18K White Gold: Which Should Men Choose for Diamond Jewellery?
Meridian Men's Emerald-Cut Tennis Bracelet
Carat weight is fixed at 0.25ct per stone, so the four metal options show the ladder in its purest form, platinum included.
From HK$31,000
View productDoes one product give the same premium at every carat weight?
The Essential Diamond Solitaire Studs offer 9K, 14K, 18K and PT950. Compare the two ends of that range, 9K white gold against 18K white gold, priced per pair:
- 0.5ct: HK$4,300 to HK$5,300. Difference HK$1,000, or 23%.
- 1.0ct: HK$5,700 to HK$7,500. Difference HK$1,800, or 32%.
- 1.5ct: HK$9,000 to HK$10,500. Difference HK$1,500, or 17%.
- 2.0ct: HK$11,500 to HK$13,000. Difference HK$1,500, or 13%.
Same product, same two metals, and the premium runs from 13% to 32%. It does not even move in one direction: it climbs to the 1.0ct pair, then falls away. No rule can be extracted from that, and that is exactly the point. Anyone who tells you white gold "adds about a quarter" is quoting one variant and calling it a law.
Essential holds one more twist. 18K white gold and PT950 platinum are priced identically at every carat weight, so a 0.5ct pair is HK$5,300 in either. On Meridian, platinum is the cheaper of those same two metals. Same brand, same pair of metals, opposite answer, decided by the piece.
On Essential, stones of 0.5ct and above are individually IGI-certified.
Essential Diamond Solitaire Studs
The clearest proof that no percentage rule exists: one product, two metals, a premium anywhere from 13% to 32%.
From HK$2,300
View productWhen does the metal cost nothing at all?
The Axiom Diamond Cross Pendant is HK$6,000 in PT950 platinum, and HK$6,000 in 18K white, rose or yellow gold. The metal choice moves the total by zero.
The general principle behind that: the less metal a design carries, the less the metal choice can move the price. Axiom is a fine pendant rather than a heavy one, so the diamond and the making dominate the number. On a bracelet holding dozens of stones in a continuous line of metal, the same choice has far more to work with.
Axiom Diamond Cross Pendant
Platinum or 18K in three colours, all at one price. On a fine design, the metal choice has almost nothing to move.
HK$6,000
View productDo yellow and rose gold cost more than white?
Not here. The Aura Linear Diamond Ear Cuff is HK$3,199 in 9K white gold, 9K yellow gold and 9K rose gold. Three colours, one price. At 18K, all three are HK$4,500.
So the colour is free and the karat is not. That step from 9K to 18K is HK$1,301, or 41%, the steepest proportional metal jump among these pieces, and it turns up on one of the smallest of them. Aura is sold as a single.
Aura Linear Diamond Ear Cuff
White, yellow and rose cost the same inside each karat, but 9K to 18K is the biggest proportional jump on this page.
From HK$3,199
View productCan you always choose the cheaper metal?
Often you cannot, because the option is not offered on that piece. What each one actually lets you pick:
- Meridian Men's Emerald-Cut Tennis Bracelet: 9K, 14K, 18K, PT950
- Essential Diamond Solitaire Studs: 9K, 14K, 18K, PT950
- Seamless Diamond Tennis Bracelet: 9K, 18K, PT950, with no 14K
- Statement Diamond Solitaire Studs: 18K and PT950 only
- Aura Linear Diamond Ear Cuff and Continuum Pavé Diamond Ear Cuff: 9K and 18K, each in white, yellow and rose, with no platinum
- Axiom Diamond Cross Pendant: PT950 and 18K in white, rose and yellow, with no 9K and no 14K
- Origin Diamond Solitaire Studs: S925 sterling silver, platinum-plated, only
- Vanguard Men's Diamond Solitaire Studs: S925 or PT950, nothing in between
Budget planning starts there. If you were counting on 9K to bring a piece within reach, first check that 9K exists on it.
Why does this need settling before you order?
Every piece is made to order in 2 to 3 weeks, with tennis bracelets and necklaces taking up to 4 weeks. Carat Club Co. does not take returns. There is one year of free repair and a 7-day exchange on a manufacturing defect, but the metal you choose is the metal you keep. Five minutes on the variant selector is worth more than an assumption.
Frequently asked questions
How much more does 18K gold cost than 9K gold?
It depends entirely on the piece. On the Meridian bracelet at 17cm, HK$34,000 to HK$44,000, a 29% step. On the Aura ear cuff, HK$3,199 to HK$4,500, a 41% step. On the Essential studs it lands anywhere between 13% and 32% depending on the carat weight.
Is platinum cheaper than 18K white gold at Carat Club Co.?
On the Meridian bracelet, yes, by HK$2,500 at 17cm, and it undercuts 18K at every length offered. On the Essential studs the two are priced identically. On the Axiom pendant they are also identical, at HK$6,000. This reflects pricing at the time of writing and can change as material costs change.
Does every product offer 14K?
No. Meridian and Essential offer 9K, 14K, 18K and PT950. The Seamless Diamond Tennis Bracelet skips 14K and offers 9K, 18K and PT950. The Statement Diamond Solitaire Studs are 18K and PT950 only.
Does rose or yellow gold cost extra?
On the Aura ear cuff, no. White, yellow and rose are the same price within each karat. The Axiom pendant is likewise HK$6,000 in 18K white, rose or yellow.
What sets the entry price of a piece?
The metal ladder the product actually offers. Essential starts from HK$2,300 for a single 0.5ct stud in 9K white gold. Aura starts from HK$3,199. Meridian starts from HK$31,000 at 15cm in 9K. Origin studs sit in S925 sterling silver with platinum plating, the only metal that piece offers.
Open the product page, switch the metal on the variant selector and watch the price. That is the only reliable way to know what the metal costs on the piece you want, because the ladder is built per piece.
