How to Choose a Diamond in Australia

The Complete Guide by Promise Me by Harry Georje

Choosing a diamond is the beginning of something extraordinary.

If you’re wondering how to choose a diamond in Australia, you’re not alone. Whether you’re planning a proposal, creating a bespoke heirloom, or simply learning how to choose a diamond in Australia, understanding the fundamentals will help you make a confident decision.

At Promise Me by Harry Georje, we believe that every diamond holds a story — and the one you choose should reflect your love, your style, and your future.

In this guide, we walk you through the 4Cs, diamond shapes, certification standards, and other essentials to help you select a stone that shines as bright as your intention.

What Are the 4Cs of Diamonds?

The 4Cs—Cut, Colour, Clarity, and Carat Weight—are the global standard for evaluating diamond quality. Mastering these four characteristics will help you choose a stone that suits your taste, values, and budget.

Understanding the 4Cs is essential when learning how to choose a diamond in Australia.

Cut – Where the Sparkle Comes Alive

The cut is the most important of the 4Cs when it comes to a diamond’s brilliance. It determines how light interacts within the stone, affecting how much it sparkles. A well-cut diamond will appear lively and eye-catching, even from across the room.

Cut Grades:

  • Excellent – Unmatched brilliance and fire
  • Very Good – Reflects most light beautifully
  • Good – Balanced choice, good value
  • Fair/Poor – Less sparkle, lower quality

Pro Tip: Always prioritise cut quality. A superior cut can make a smaller diamond appear larger and brighter.

Diamond 4Cs guide – cut, colour, clarity, and carat by Promise Me by Harry Georje
Diamond 4Cs guide – cut, colour, clarity, and carat by Promise Me by Harry Georje
Popular diamond shapes – round, oval, pear, emerald, and cushion cuts
Popular diamond shapes – round, oval, pear, emerald, and cushion cuts

Colour – Where the Sparkle Comes Alive

Diamond colour is graded based on how colourless the stone is. The scale runs from D (colourless) to Z (light yellow or brown). The less colour a diamond has, the higher its value—though many stones between G and J appear colourless to the naked eye.

Colour Grade Guide:

  • D–F: Colourless – Icy white, rarest
  • G–J: Near Colourless – Excellent value, ideal for white gold or platinum
  • K–M: Faint Colour – Warmer tone, works well with yellow or rose gold

Pro Tip: Choosing near-colourless diamonds offers a clean look without paying top-tier prices.

Clarity – The Diamond’s Natural Fingerprint

Clarity refers to the presence of internal inclusions and surface blemishes. Most diamonds have tiny marks caused during their formation, and many are invisible without magnification.

Clarity Grade Overview:

  • FL–IF: Flawless or Internally Flawless – Ultra rare
  • VVS1–VVS2: Very, Very Slightly Included – Exceptional clarity
  • VS1–VS2: Very Slightly Included – High quality with excellent value
  • SI1–SI2: Slightly Included – Eye-clean in most cases
  • I1–I3: Included – Imperfections visible to the naked eye

Pro Tip: Look for diamonds with inclusions at the edges—they’re less visible once the stone is set.

GIA diamond certification example – trusted grading standards in Australia
GIA diamond certification example – trusted grading standards in Australia
Custom engagement ring design process - Promise Me by Harry Georje
Custom engagement ring design process - Promise Me by Harry Georje

Carat Weight – Size and Presence

Carat refers to the diamond’s weight, not its size. While many buyers prioritise carat weight, a beautifully cut diamond of a lower carat can still look stunning and appear larger.

Did you know? One carat equals 200 milligrams. Prices jump at popular sizes (e.g. 1.00ct, 1.50ct), so shopping just under can stretch your budget further.

Pro Tip: Try a 0.90ct instead of 1.00ct—same visual impact, lower price tag.

Choosing the Right Diamond Shape

The shape is what gives your diamond its character. It’s a matter of personal preference, and each shape offers its own style and visual effect.

Most Popular Diamond Shapes in Australia:

  • Round Brilliant – Classic, maximum sparkle
  • Oval – Modern elegance, flattering on the hand
  • Princess – Sharp and contemporary
  • Cushion – Soft, vintage-inspired charm
  • Emerald – Sophisticated and art deco
  • Pear, Marquise, Asscher, Radiant, Heart – Distinctive and personal

Pro Tip: Fancy shapes (non-round) often appear larger per carat and offer unique flair at better value.

Diamond Certification: Proof of Quality

Always insist on an independently certified diamond. Certificates from reputable labs guarantee your diamond’s specifications.

Top International Grading Labs:

  • GIA (Gemological Institute of America) – The gold standard
  • IGI (International Gemological Institute)
  • AGS (American Gem Society)

Pro Tip: At Promise Me by Harry Georje, all diamonds come with full certification, so you know exactly what you’re buying.

Natural vs Lab-Grown Diamonds in Australia

We offer both natural diamonds and lab-grown diamonds, and both are 100% real.

  • Natural Diamonds – Formed underground over billions of years.
  • Lab-Grown Diamonds – Created in high-tech labs, identical in composition and sparkle.

Lab-grown diamonds are more affordable, ethically sourced, and environmentally friendly—making them a brilliant choice for conscious buyers.

Pro Tip: A 1.5ct lab-grown oval diamond can cost the same as a 1.0ct natural—without compromising on brilliance.

How to Set Your Diamond Budget

Shopping smart means understanding where to save and where to splurge. Here’s how:

  1. Decide your total budget first.
  2. Prioritise the 4Cs—Cut is key, Colour and Clarity can be flexible.
  3. Try just under magic numbers (0.90ct vs 1.00ct).
  4. Opt for lab-grown for bigger size at lower cost.
  5. Choose a shape that gives more size per carat (oval, pear, cushion).

Current Engagement Ring Trends in Australia

  • Hidden Halos and custom settings
  • Oval and elongated shapes (inspired by celebs like Hailey Bieber)
  • Lab-grown diamonds for sustainability and savings
  • Mixed metals and personalised engravings
  • Ethical sourcing is a must for modern couples

Why Buy from Promise Me by Harry Georje?

At Promise Me by Harry Georje, we blend luxury with transparency. Whether you’re browsing our range online or seeking a bespoke design, we’re here to guide you through one of life’s most meaningful purchases.

  • ✅ Australian-owned
  • ✅ Ethically sourced diamonds
  • ✅ Natural & lab-grown options
  • ✅ Certified stones only
  • ✅ Tailored customer support
  • ✅ Flexible payment options available

Still unsure which diamond is right for you?

That’s perfectly normal — and we’re here to help. Whether you’re drawn to a timeless round cut or exploring lab-grown alternatives, the journey to the perfect diamond is a personal one.

This guide is designed to help you feel confident in how to choose a diamond in Australia, no matter your style or budget.

✨ Explore our Engagement Ring collection,
✨ Shop by Diamond Shape, or
✨ Request a Custom Design

to begin your story with Promise Me by Harry Georje.

And if you’re curious about certifications or advanced diamond grading, we recommend visiting the Gemological Institute of America (GIA) for additional guidance.