Melee Diamond Size Chart for Jewellers: Millimetres, Carat Weight and Tolerances
Last reviewed
Dalila's general Diamond Size Chart is intended primarily to help buyers understand how larger loose natural diamonds translate from carat weight into approximate face-up dimensions across different shapes.
This page has a different purpose.
The Melee Diamond Size Chart is for professional production planning.
It focuses on:
millimetre calibration, approximate weight per small round stone, pieces per carat, parcel ordering and manufacturing tolerances.
The two pages should link to one another but should not target the same primary keyword.
The Dalila Melee Ordering Framework
For professional buyers, start with the jewellery rather than the parcel.
Determine the actual stone diameter required by the CAD or setting.
Then define the tolerance the setter can accept.
Specify the cutting style, colour and clarity band.
Estimate the required number of stones.
Use the chart to estimate total carat weight.
Add the production spare requirement.
Then ask the supplier to confirm the actual calibrated weight and quantity available.
Once the parcel arrives, reconcile count, weight, measurements and grade before releasing the goods to production.
For natural melee, maintain a separate origin-screening control.
This workflow keeps millimetres, carats and production requirements aligned.
Common Melee Size-Chart Mistakes
The first common mistake is treating the chart as though every 2.00 mm diamond weighs exactly 0.030 ct.
It does not.
Another is ordering by point weight instead of the setting's millimetre requirement.
A third is using total carat weight as a substitute for stone count.
Buyers also sometimes specify “calibrated” without writing down the actual acceptable tolerance.
Another problem is applying round-diamond conversions to fancy-shaped melee.
Likewise, stars, fulls and pointers should not replace millimetres in a modern manufacturing RFQ.
Finally, do not assume a size-sorted natural parcel has also been screened for origin.
Sizing and diamond identification are separate quality-control functions.
Final Answer: What Is the Best Way to Order Melee Diamonds?
For jewellery manufacturing, order melee using the millimetre size required by the setting.
Use approximate carat weight to estimate cost and parcel weight.
Use pieces per carat to estimate quantity.
Then specify the dimensional tolerance explicitly.
For example:
1.50 mm round natural full-cut melee, ±0.03 mm, G–H, VS range
is a far more useful production specification than:
approximately 1.5-point diamonds.
Carat remains essential for weighing and pricing.
Millimetres remain essential for fit.
Count remains essential for production.
Tolerance determines whether the parcel behaves consistently at the bench.
And natural-origin screening determines whether a natural-diamond parcel is correctly represented.
A professional melee order therefore needs all of those controls working together.
Source Natural Melee and Production Diamonds with Dalila
Dalila Diamonds works with professional buyers sourcing natural diamonds for jewellery production from Antwerp.
A trade sourcing brief can include the required shape, nominal millimetre size, calibration tolerance, quantity, colour, clarity, cutting style, quality requirement, destination and deadline.
Where a specific production requirement is not available in existing inventory, DS4U – Diamond Source For You can be used to source against the required commercial specification.
Frequently Asked Questions About Melee Diamond Sizes
What size is a melee diamond?
GIA defines melee as diamonds weighing less than 0.20 ct, although actual commercial definitions vary between markets and trade sectors.
How small can melee diamonds be?
Melee can be extremely small. GIA notes that some melee may weigh as little as approximately 0.001 ct.
How many millimetres is a 0.01 ct round diamond?
A normally proportioned round near one point may be approximately 1.25–1.4 mm, depending on its depth and make.
How many carats is a 1 mm melee diamond?
A normally proportioned 1.0 mm round may weigh approximately 0.004–0.005 ct.
How many carats is a 1.5 mm diamond?
A normally proportioned 1.5 mm round may weigh roughly 0.012–0.015 ct.
How many carats is a 2 mm round diamond?
Approximately 0.03 ct is a useful trade estimate for a normally proportioned 2.0 mm round diamond.
How many carats is a 2.5 mm diamond?
A normally proportioned 2.5 mm round may weigh approximately 0.055–0.060 ct.
How many carats is a 3 mm round diamond?
Approximately 0.10 ct, or ten points, is a useful reference for a normally proportioned 3.0 mm round.
How many carats is a 4 mm round diamond?
Depending on its actual proportions, a 4.0 mm round can be around 0.23–0.25 ct.
How many 1 mm diamonds are in one carat?
Approximately 200–250 normally proportioned 1.0 mm round diamonds may make one carat.
How many 1.5 mm diamonds make one carat?
Approximately 65–80 stones is a useful working estimate.
How many 2 mm diamonds make one carat?
Approximately 32–34 normally proportioned 2.0 mm rounds make one carat.
How many 2.5 mm diamonds make one carat?
Approximately 17–18 stones is a useful reference.
How many 3 mm diamonds make one carat?
Approximately ten normally proportioned 3.0 mm round diamonds make one carat.
Is melee sold by pieces or carat weight?
Melee is commonly priced and sold by parcel weight, but production orders may also require a specified piece count.
What is a diamond point?
One point equals 0.01 ct. One hundred points equal one carat.
What is calibrated melee?
Calibrated melee is size-sorted to fall within an agreed dimensional tolerance around a nominal millimetre size.
What is a normal melee calibration tolerance?
There is no universal tolerance. Current suppliers publish specifications ranging from very tight ±0.02 mm programmes to ±0.05 mm or wider depending on application.
Is ±0.05 mm suitable for pavé?
It may be suitable for some programmes, while precision micro-pavé or engineered settings may require tighter control. The setter or CAD should determine the necessary tolerance.
Is millimetre size more important than carat weight for melee?
For setting fit, yes. Carat weight remains essential for pricing and parcel totals, but the millimetre dimension determines whether the stone fits the intended seat.
Can two 2 mm diamonds have different carat weights?
Yes. Differences in depth, girdle thickness and proportions can cause stones with the same face-up diameter to weigh differently.
Are melee size charts exact?
No. They are approximate conversion references. Exact diamond weight must be established using a calibrated scale.
Can I use a round melee chart for princess or baguette diamonds?
No. Fancy shapes distribute weight differently and should be specified by the dimensions appropriate to that shape.
What is full-cut melee?
Full-cut round melee uses a more complete brilliant-style facet arrangement than single-cut melee and is widely used in modern jewellery.
What is single-cut melee?
GIA describes a single cut as normally having 17 or 18 facets depending on whether a culet is present.
What are stars and fulls?
They are traditional trade descriptions for different small melee size bands. Usage varies between suppliers, so the actual millimetre specification should always be confirmed.
What are pointer diamonds?
Pointers are diamonds described using point weight. For example, a 10-pointer weighs approximately 0.10 ct.
Do natural melee diamonds need screening?
For a natural-only supply programme, appropriate screening is important because size sorting and visual parcel inspection do not reliably establish natural origin for every stone.
Does GIA screen melee diamonds?
Yes. GIA currently offers a Melee Analysis Service for eligible stones between 0.9 and 4.0 mm, approximately 0.005–0.25 ct.
How should I order melee for a CAD design?
Provide the nominal millimetre size, accepted tolerance, shape, cutting style, quantity, colour, clarity, natural-origin requirement and any setting-specific depth or geometry requirements.