Diamond Price Guide - Diamond Costs in Australia Explained

Diamond Price Guide - Diamond Costs in Australia Explained

The cost of diamonds in Australia is determined by the cut, colour, clarity, and carat of the diamond – otherwise known as the 4Cs of diamonds. Whether you’re investing in loose, wholesale diamonds or purchasing diamonds on the retail market, understanding diamond prices is essential.

In this guide, we’ll look at the factors influencing diamond prices, how much you can expect to pay for a diamond in Australia, and the market factors that you need to understand when purchasing diamonds.

How much does a diamond cost in Australia?

This is a tricky question — one that diamond buyers ask all the time. The reason why this question is difficult to answer is due to the range of factors that influence the price of a diamond, namely the 4 Cs, as well as global shifts in the supply of diamonds. 

Taking a look at our own collection of diamonds at GS Diamonds, the cost of a diamond ranges from $1000, up to over $1 million. With such a wide price range, it’s important to understand what to look for in a diamond, and how these factors can affect their cost. 

The 4 C's of Diamonds from GS Diamonds

Factors that influence the costs of diamond in Australia

Aside from external market factors, there are 4 main factors that you should keep in mind when shopping for a diamond: Cut, Colour, Clarity, and Carat. Here’s a detailed look at each of these:


A diamond’s cut is responsible for the brilliance and sparkle of a diamond. Not to be confused with diamond shape, which refers to the outline of a diamond (i.e. round, oval, cushion), the cut of a diamond is what gives it the ability to reflect light in a spectacular way. All diamonds are processed through a meticulous cutting and polishing stage to achieve the signature shine. 

There are 4 general gradings of diamond cut: Excellent, Very Good, Good, and Fair. The better the diamond cut grade, the higher a diamond’s value and price will be. The pinnacle of diamond cut is the triple-excellent cut, where a diamond achieves the highest grade for overall cut quality, polish, and symmetry. 


Due to the presence of trace elements during formation, most diamonds naturally come in slight shades of yellow. For colourless diamonds, a lack of this colour is what makes a diamond more valuable. 

Diamond colour is graded on a scale of D to M, with D indicating complete colourlessness and M representing a very noticeable yellow tinge. The more colourless a diamond, the higher it will tend to cost.


Diamond clarity is the measure of physical inclusions and blemishes within and on the surface of a diamond. These inclusions and blemishes can often negatively affect the brilliance and fire of a diamond and are undesirable. Clarity for diamonds is rated on a scale from Flawless (FL) to Slightly Included (SI), with flawless diamonds being the most valuable and costly. 

The key thing to note here is that while inclusions are found in most diamonds, a handful of them are too small to be detected with the naked eye and are only visible under 10x magnification. Diamonds with no visible inclusions without magnification are considered “eye-clean” (starting from a clarity rating of VS2, moving upwards) — these diamonds are considered to have the best value to purchase. 


Carat, or carat weight, is the measure of a diamond’s size. 1 diamond carat is equal to 200 milligrams. The higher the carat weight of a diamond stone, the larger and more visible it will be, and also more costly. 

When buying a diamond, be sure to pay attention to each of these factors. Finding the right balance of the 4 Cs is the best way to shop for a diamond as each of them directly contributes to the cost and overall quality of the diamond.

How to calculate the cost of a diamond?

As we’ve seen above, the cost of a diamond is generally determined by how it is graded based on the 4 Cs. Since each diamond’s characteristics differ greatly from one another, there is no definitive way to calculate diamond cost. The 4 Cs are more of a general guide to how costs differ between diamonds. 

Factors influencing the value of a diamond cut from GS Diamonds

Most diamond suppliers (like us) have online stores where you can browse and filter your search from a collection of diamonds that are categorised according to the 4 Cs. This way, you can make comparisons between similar priced diamonds or find a diamond that fits your specific preferences. 

How much does a 1ct diamond cost in Australia?

In Australia, the cost of a 1ct diamond can range from $2,400 to $27,000, depending on how it has been graded for cut, colour, and clarity. Buying a “good” diamond ultimately comes down to your budget and what your preferences are for the stone. 

Are the costs for diamonds in Australia competitive?

Diamond prices are very competitive here in Australia. At GS Diamonds, we do our best to keep the cost of our diamonds matched as close as possible to their market value to give you a good idea of how much they are worth, and to help you pay only for the value of the diamond.  

Do the costs of diamonds fluctuate?

Like any other precious commodity, the prices of diamonds do fluctuate based on laws of supply and demand. As of June 2023, the price of diamonds was reported by the Global Rough Diamond Price Index to have dropped by 18% since February 2022. 

Start your diamond search at GS Diamonds

The cost of a diamond is not always an accurate representation of its “worth” to you as a buyer. Finding the perfect diamond is more about understanding what you want in a diamond, and how it matches up to available options. 

With the help of this price guide and our diamond specialists at GS Diamonds, you will be able to navigate our extensive collection of quality diamonds to find the ideal stone, whether it’s for an engagement ring or a necklace. Book an appointment at our diamond showrooms in Sydney or Melbourne today to start your search for the perfect diamond!

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