THE GEM ACADEMY
PART 2: Quality & Shape
Welcome to the eagerly anticipated second installment of our online report! This time, we're focusing on shapes and qualities of laboratory-grown diamonds. Discovered through the analysis of major wholesale platforms. Let's go!
The qualities of laboratory-grown diamonds are increasing every year. The findings of this report may surprise you as the qualities are even better than expected!
Let's find out the common colours, clarities, and shapes of laboratory-grown diamonds on the market.
This report utilises multiple resources to bring you these insights. We'll mainly focus on data obtained from one major online wholesaler and more than 300,000 stones.
This information is correct for 15/03/2023.
Laboratory-grown diamonds in numbers
Overall, the equivalent colour grades of laboratory-grown diamonds are exceptionally high. The majority of them are completely colourless.
This report finds that 65% of laboratory-grown diamonds are equivalent to D-E-F colour grades.
Approximately 2% are equivalent to 'J' or below.
Breakdown of HPHT v CVD colour grades
HPHT colour grades
Nearly 95% of HPHT laboratory-grown diamonds traded today are equivalent to D-E-F colour grades.
This has increased over the last 6 years. In 2017, GIA reported that 72% of HPHT laboratory-grown diamonds were in the D-E-F 'colourless' range.
The most common colour grade for HPHT laboratory-grown diamonds is 'D' - the highest colour grade possible.
This accounts for 57.7% of the HPHT-grown stones available.
CVD colour grades
In 2016, GIA reported that the majority (67%) of CVD laboratory-grown diamonds were 'near colourless' - equivalent to G-J colour grades.
CVD laboratory-grown diamonds have typically exhibit lower colour grades compared with HPHT-grown stones due to the CVD growth method resulting in internal strain.
This report reveals that the majority has shifted into the 'colourless' range. Nearly 51.9% of CVD laboratory-grown diamonds being traded today are within the D-E-F colour grades.
The most common colour grade for CVD laboratory-grown diamonds is 'F'. This accounts for 29.4% of CVD-grown stones available.
A note on treatments for CVD
Most CVD laboratory-grown diamonds are treated post-growth to remove colour (from brown to more colourless). This information is rarely included on laboratory-grown diamond reports which instead offer over-disclosure statements such as "this laboratory-grown diamond may have been subjected to post-growth treatments". Therefore, it is with regret, that no new data is available on treatments in this report.
It has been estimated that approximately 75% of 'colourless' to 'slightly tinted' CVD laboratory-grown diamonds on the market have been treated to remove colour.
90% of all laboratory-grown diamonds on the wholesale market have a clarity grade equivalent to VS and above. The most common clarity grade is VS1.
Less than 0.2% have grades within the 'Included' range (I1-I3).
Less than 0.5% have grades equivalent to 'Flawless' and 'Internally Flawless'.
HPHT v CVD
CVD laboratory-grown diamonds have historically had a better reputation for clarity grades compared to HPHT.
This is not valid today as HPHT laboratory-grown diamonds have a similar dispersion of clarity (if not a little bit better overall).
HPHT synthesis produces significantly more stones in the VVS range.
The most common clarity grade for both HPHT and CVD laboratory-grown diamonds is VS1.
HPHT also produces more stones in the SI range but only by a small percentage. Less than 10% of stones on the market for both CVD and HPHT have clarity grades of SI1 and below.
Cut & Shape
The most common shape available is round brilliant followed by oval and pear cuts.
The vast majority of laboratory-grown diamonds have equivalent cut-grades to 'excellent'.
An attributing factor is the relatively low value of the product. Stones can be cut for beauty as opposed to retaining maximum yield from the rough crystal.
Another factor is the increased use of automated cutting processes.
Most laboratory-grown diamonds have an 'EXCELLENT' cut grade.
Interesting shapes of laboratory-grown diamonds are on the market.
This leaf design is available from
Fire Diamonds. It utilises large shallow crystals being created by CVD synthesis.
The availability of the material along with the reduced need to maximise yield will open opportunities for many new cut designs.
'Hamsa' shape by Fire Diamonds
'Buddha' shape by Lab Grown Diamonds USA
Letters by Lab Grown Diamonds USA
Photo credit: GIA
New record-breaking sizes
In May 2023, GIA announced that they assessed this 34.59ct G, VS2 emerald-cut grown by Ethereal Green Diamonds.
This is the largest laboratory-grown diamond to be confirmed by a producer or grading laboratory.
There has been a report of a 38ct oval.
Watch this space.
24.94 × 13.95 × 9.39mm
I hope you enjoyed this report.
Come back for Part 3: Price
Releasing June 2023
THE GEM ACADEMY
Data taken 15/03/2023 unless otherwise stated.
© Julia Griffith
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