Your guide from the team at TMC Fine Jewellers. Collectively, our team has over 250 years of experience in the jewellery industry, from master jewellers, to designers and gemstone setters.
Choosing a diamond is one of the most considered decisions within the engagement ring process. It is not simply about finding a stone that looks beautiful — it is about understanding what makes a diamond truly exceptional, and ensuring every detail has been selected with intention.
Every client who purchases an engagement ring through our New Farm showroom has their diamond hand-selected by our Gemstone Specialist, Poppy. This guide reflects the same criteria Poppy applies to every stone she considers — so that whether you are exploring independently or working alongside our team, you can move forward with clarity and quiet confidence.
Start with the certificate
Every diamond Poppy considers must be certified by either the GIA (Gemological Institute of America) or the IGI (International Gemological Institute). These are the two most respected grading laboratories in the world, and their certificates provide an independent, standardised assessment of a stone's quality.
Certification is not simply paperwork. It is the foundation of trust — confirmation that the qualities attributed to a stone have been verified by an expert outside of the supply chain. We will not consider a diamond without it.
Beyond the certificate, every stone must be accompanied by both a high-resolution image and a video. Seeing a diamond move — watching how it interacts with light from every angle — is essential to understanding its true character before it is selected for you.
Our standards, at a glance
The criteria below apply to every diamond Poppy hand-selects, regardless of shape, size, or budget. There are no exceptions.
|
What we look at |
Our standard |
|---|---|
|
Certification |
GIA or IGI only |
|
Eye clean |
100% — no visible inclusions to the naked eye |
|
Image & video |
Both required before a stone is considered |
|
Polish |
Excellent |
|
Symmetry |
Excellent |
|
Colour |
D, E, or F — colourless range only |
|
Clarity |
IF, VVS1, VVS2, VS1, or VS2 |
|
Carat weight |
0.50ct – 8.00ct |
Understanding colour
Colour in a diamond refers to the absence of colour. The GIA and IGI both grade diamonds on a scale beginning at D (completely colourless) and descending through the alphabet as subtle warmth becomes detectable.
At TMC Fine Jewellers, Poppy selects only from the D, E, and F colour range — collectively known as the colourless tier. These three grades are indistinguishable to the naked eye, but each carries its own character. A D colour diamond is the rarest and most prized. E and F offer the same visual purity with a slightly more considered price point, which is why they are frequently chosen by clients who wish to direct more of their budget toward carat weight or setting detail.
Within our Brisbane clientele, E colour has been a consistent favourite — exceptional in quality, and considered in value.
Understanding clarity
Clarity describes the presence — or absence — of internal characteristics within a diamond, known as inclusions. Every diamond in nature forms under immense heat and pressure, and most carry some record of that process.
Poppy selects only from the IF (Internally Flawless), VVS1, VVS2, VS1, and VS2 clarity grades. Across all of these, our most important requirement is that every stone must be 100% eye clean. This means no inclusion is visible to the naked eye under normal viewing conditions. A VS2 in our collection will appear just as flawless face-up as an IF — the distinction lives under magnification, not in everyday wear.
For clients focused on optimising size within their budget, VS1 and VS2 represent an exceptional choice. For those who prefer the reassurance of the very finest specifications, VVS2 and above offer an additional layer of distinction.
|
D |
E |
F |
Colour grades we carry |
|---|---|---|---|
|
Absolutely colourless |
Exceptional white |
Rare white |
All three grades are considered colourless and are indistinguishable to the naked eye. D is the rarest; E and F offer exceptional quality at a slightly more attainable price point. |
|
IF |
VVS1 / VVS2 |
VS1 / VS2 |
Clarity grades we carry |
|
Internally Flawless |
Very Very Slightly Included |
Very Slightly Included |
Every stone across all clarity grades must be 100% eye clean. The difference between IF and VS2 lives entirely under magnification — face up, each is flawless to the eye. |
The importance of cut
Cut is perhaps the most influential of all diamond qualities. It is what determines how a stone interacts with light — its brilliance, fire, and the way it comes alive on the hand.
Every diamond Poppy selects must achieve Excellent in both polish and symmetry. Polish describes the quality of the diamond's surface finish; symmetry, the precision of its facet alignment. Together, they define how refined a stone truly is.
Beyond these gradings, each diamond shape has a specific table percentage and depth percentage range within which it performs at its best. These are the proportions that allow light to enter, reflect internally, and return to the eye — rather than escaping through the sides or base of the stone.
The table below outlines the proportion ranges Poppy applies to each shape. Stones that fall outside these windows, however beautiful they may appear on paper, are not considered.
Shape-by-shape proportion guide
|
Shape |
Also known as |
Table % |
Depth % |
Ideal Ratio |
|---|---|---|---|---|
|
Round |
— |
53–58% |
59–62.3% |
|
|
Oval |
53–63% |
58–62% |
1.25-1.60 |
|
|
Marquise |
— |
53–63% |
58–62% |
1.70-2.40 |
|
Pear |
— |
53–63% |
58–62% |
1.25-1.60 |
|
Cushion |
Cushion Modified, Cushion Brilliant, Old Miner |
61–67% |
61–67% |
|
|
Emerald |
— |
61–69% |
61–67% |
1.25-1.60 |
|
Radiant |
— |
61–69% |
61–67% |
1.25-1.60 |
|
Asscher |
— |
61–69% |
61–67% |
|
|
Moval |
— |
53–63% |
58–62% |
1.70-2.10 |
|
Elongated Cushion |
— |
61–67% |
61–67% |
>1.10 |
A note on shape names
Two shapes within our Signature Range carry names that reflect more than their cut — they describe their proportions.
Elongated Cushion: A cushion-cut diamond with a length-to-width ratio above 1.10. It retains the soft, rounded corners characteristic of the cushion shape, while offering a more slender, finger-flattering silhouette. A beautiful choice for those drawn to the cushion aesthetic but seeking a more elongating effect.
Moval: An oval diamond with a length-to-width ratio between 1.70 and 2.10 — sitting visually somewhere between a classic oval and a marquise. It is increasingly sought-after for the dramatic, elongating presence it creates on the hand, and carries a quietly distinct character all of its own.
Choosing a carat weight
Carat weight is one of the most visually defining elements of a diamond, though it is rarely considered in isolation. As with engagement ring design more broadly, the most important question is not how large a stone is — but how it looks and feels on the hand.
Poppy selects diamonds across a range of 0.50ct to 8.00ct, ensuring there is a stone suited to every setting, style, and occasion. Within our Brisbane clientele, stones between 1.5ct and 3ct remain the most commonly chosen — a range that balances visual impact with proportion and wearability.
Carat weight tells you the size of a stone. Proportion tells you how beautifully it performs. Poppy considers both in equal measure.
To give you a sense of investment across this range, the table below outlines stone-only pricing from entry level through to the finest specifications, alongside our standard — E colour, VS1 clarity — which represents the balance of quality and value most frequently chosen by our clients.
|
Carat |
Price range (stone only) |
E, VS1 — our standard |
|
1.5ct |
$1,750 – $4,410 |
$1,970 |
|
2.0ct |
$2,230 – $6,670 |
$2,400 |
|
2.5ct |
$2,750 – $9,350 |
$3,090 |
|
3.0ct |
$3,260 – $10,900 |
$3,690 |
Prices reflect the stone only and do not include setting or customisation. All pricing is in AUD.
Carat weight tells you the size of a stone. Proportion tells you how beautifully it performs. Poppy considers both in equal measure.
Every diamond selected for our clients has cleared each of these criteria — without exception.
When Poppy selects a stone for you, you can be confident that what you are receiving has been considered, verified, and chosen with the same care you would apply yourself — if you had the expertise to do so. That is precisely the point.
Explore our Signature Range or secure a consultation at our New Farm showroom to begin the process.
