Latest 12.5 carat diamond price update 2026

12.5mm diamonds are among the rarest and most valuable sizes in the jewelry market today. With a diameter of approximately 12.5mm and an average weight of 7.5-8.5 carats, each diamond not only possesses timeless sparkle but also symbolizes power, prosperity, and personal status. 

In this article, Jemmia will help you better understand the value, meaning, and how to convert carats for 12.5mm diamonds to have a comprehensive view before making a purchase.

How much is a 12.5mm Diamond?

The price of a 12.5mm diamond ranges from 14.4 billion VNĐ to 60 billion VNĐ. The price of a 12.5mm diamond can vary greatly based on the 4Cs factors: 

• A 12.5mm diamond with D color, FL clarity, and Excellent cut is priced on the market at approximately 28.8 billion VNĐ – 60 billion VNĐ.
• A 12.5mm diamond with G color, VS1 clarity, and Very Good cut is priced on the market at approximately 19.2 billion VNĐ – 28.8 billion VNĐ.
• A 12.5mm diamond with I color, SI1 clarity, and Good cut is priced on the market at approximately 14.4 billion VNĐ – 19.2 billion VNĐ.

Each 12.5mm diamond is a unique work of art, with no two stones being exactly alike. Differences in clarity, color, and cut create a distinct mark for each 12.5mm diamond, making their value not simply determined by size.

Note: The above price list is for reference only. In case of scarce supply, diamond prices may increase sharply in the future. See now: Updated diamond price list or Contact Jemmia immediately: 0838 353 333

What is a 12.5mm diamond in carats?

In the jewelry industry, "ly" is used to denote the diameter of a diamond (1 ly ≈ 1mm), while carat is a unit of weight (1 carat = 0.2 grams). For a diamond with a diameter of 12.5mm (12ly5), the weight typically falls between 7.5-8.5 carats, depending on the cut proportions and depth of the stone.

Why can carats differ for the same 12.5mm size?

Not all diamonds of the same diameter will have the same weight. This depends on:

• Cut: If a diamond is cut deep, its weight (carat) will be heavier. Conversely, if it's cut shallow, the carat will be lighter even with the same diameter.
• Shape: A standard Round Brilliant diamond typically has a higher carat than Fancy shapes (oval, cushion, emerald...) of the same face size.
• Proportion: The balance between the diameter, height, and thickness of the diamond determines its actual weight.

Let's look at the actual conversion for 12.5mm diamonds below: 

• Standard Round Brilliant Diamond (12.5mm): ~7.8 – 8.2 carats.
• Oval/Cushion Shaped Diamond (12.5mm): ~7.2 – 7.8 carats.
• Deeply cut or special cuts: Can exceed 8.5 carats.

Therefore, a 12.5mm diamond usually falls within the range of 7.5 – 8.5 carats. To determine the exact weight, you need to refer to international grading reports (GIA, IGI) – which provide complete information on the stone's weight, cut, color, and clarity.

See more: Top 10 outstanding summer 2026 rings you shouldn't miss

The Meaning of a 12.5mm Diamond

A 12.5mm diamond is not just a rare gemstone; it holds profound meanings. With its superior size and value of tens of billions of VNĐ, each 12.5mm diamond is a timeless symbol of power, prosperity, and status.

Symbol of Eternity

Diamonds have long been considered "imperishable stones," associated with eternal love and strong bonds. Owning a 12.5mm diamond means you hold proof of a proud and enduring love that lasts through the years.

Expressing Status and Power

Among entrepreneurs and successful individuals, a 12.5mm diamond is likened to a "secret passport" that affirms social standing. Its large size, rarity, and international grading reports (GIA, IGI) make the diamond the clearest statement of the owner's success and influence.

Feng Shui and Fortune Value

According to Eastern beliefs, diamonds symbolize strong energy, bringing good luck and dispelling negative energies. Especially with its 12.5mm size, the diamond also represents completeness, fulfillment, and abundant wealth – very suitable for those who wish to strengthen their fortune and expand their career path.

The meaning of a 12.5mm diamond

Where to Buy Reputable and Quality Diamonds?

When deciding to invest in or own a large diamond like a 12.5mm, the most important factor is choosing a reputable dealer. Because diamonds are luxury assets valued in billions of VNĐ, without transparent certification, buyers are very likely to make mistaken purchases, overpay, or even encounter substandard products.

Jemmia Diamond is one of the leading reputable brands in Vietnam, trusted by many domestic and international customers because:

• High 4Cs Standard Diamonds: Jemmia diamonds meet high 4Cs standards, absolutely avoiding stones with flaws affecting durability and structure, ensuring lasting asset value for customers.
• 100% Legally Imported Diamonds: All products at Jemmia come with GIA certificates and documentation, guaranteeing clear origin for your diamond.
• Transparent Inspection Process: Customers can directly inspect diamonds using modern equipment (Gemolite, GIA ID100, GIA Match ID…), ensuring authenticity.
• Exclusive Designs: Jemmia boasts a team of professional jewelry designers and craftsmen, offering luxurious and exquisite diamond ring, necklace, and earring designs.
• After-sales Policy, Competitive Buyback/Exchange: We commit to transparent buyback and exchange policies, enhancing the liquidity value of your diamond.
• Expert Brand: With many years of experience in the diamond industry, Jemmia always positions itself as a "diamond expert" – a trusted companion helping customers find their desired diamond. 

If you are looking for a high-quality 12.5mm diamond with transparent sourcing, please contact Jemmia's hotline for detailed consultation from our diamond experts.

Jemmia - A reputable diamond purchasing destination

It can be seen that a 12.5mm diamond is not just a luxurious piece of jewelry, but also a symbol of power and a sustainable investment channel. With an average weight of 7.5-8.5 carats and a price tag in the tens of billions of VNĐ, it is the perfect choice for those seeking to assert their status and enduring value. When deciding to purchase, you should prioritize reputable dealers with international grading certificates to ensure transparency and absolute peace of mind.