Coloured stones are priced by appearance rather than by a numeric grade, which makes them harder to specify than diamonds. Lab grown material removes the largest commercial risk: it can be produced to a consistent colour, so a suite or a bracelet run can actually match.
Stone-by-stone reference
| Stone | Hardness | Refractive index | Specific gravity | Specification focus |
|---|---|---|---|---|
| Emerald | 7.5–8 | 1.57–1.58 | 2.67–2.78 | Colour saturation, eye-clean clarity, no fracture filling |
| Ruby | 9 | 1.76–1.77 | 3.97–4.05 | Tone and saturation; avoid brown modifier |
| Sapphire | 9 | 1.76–1.77 | 3.95–4.03 | Evenness of colour across the parcel |
| Paraiba tourmaline | 7–7.5 | 1.62–1.64 | 3.06 | Neon cyan saturation; copper-bearing tone |
| Padparadscha sapphire | 9 | 1.76–1.77 | 3.95–4.03 | Pink–orange balance; neither dominates |
| Zircon | 7.5 | 1.92–1.98 | 4.6–4.7 | Blue and white calibrated melee |
Why calibration decides whether you can build sets
Calibrated sizes — 5×3 mm ovals, 4 mm rounds, 6×4 mm cushions — let you assemble matched suites, halos, bracelets and earring pairs without hand-sorting. Specify calibrated sizes with a tolerance in tenths of a millimetre and require the parcel sorted by size band rather than delivered as a mixed lot.
Colour consistency: the single biggest advantage of lab grown
- Establish a colour standard — retain a reference stone or a photographed master set — before the first production run.
- Confirm the standard on the approval sheet, with photographs under daylight and under a colour-corrected lamp.
- Require every subsequent run to be matched against the retained standard, not against a new production batch.
- Record the standard on your own purchase orders so a change of supplier still has a benchmark.
Care and wear guidance
- Emerald: avoid ultrasonic and steam cleaning; use warm water with mild soap and a soft brush. Not ideal for everyday rings without protective setting.
- Ruby and sapphire: durable for daily wear; ultrasonic cleaning is acceptable.
- Paraiba tourmaline: beautiful but relatively soft; best in earrings, pendants and protected settings rather than constant-wear rings.
- Padparadscha sapphire: corundum hardness, suitable for bridal.
Treatments and disclosure
Ask four questions of any coloured stone supplier: is the material as-grown or treated; is there fracture filling, oiling or dyeing; does your market require disclosure of that treatment; and will the same treatment status hold for a reorder in six months. Consistency of disclosure matters more than the absence of treatment — buyers can sell a disclosed treated stone, but not a surprise.
Specification template
Stone: lab grown emerald, vivid bluish green, eye clean, oval 6×4 mm calibrated ±0.1 mm, no fracture filling, IGI report on request; metal: 18K yellow gold, 2.4 g ±5%; setting: four-prong; MOQ 10 pcs; lead time 12–18 days.
Setting coloured stones without losses
Coloured stones vary in toughness even at similar hardness, and setting is where most damage happens. Three practical rules: use protective settings (bezels or heavy prongs) for emerald and paraiba, avoid heat-intensive soldering near the stone, and set softer stones last in a multi-stone piece. For bracelets and rings that see daily wear, prefer corundum — ruby and sapphire — over emerald and tourmaline regardless of hardness figures on paper.
Building a colour programme that sells
- Start with one or two stone types rather than a broad palette; depth beats breadth when you are establishing a look.
- Fix a colour standard with a retained reference stone and photographs under two lighting conditions.
- Order calibrated sizes so you can build suites and matched pairs from stock rather than hand-sorting.
- Price the metal separately from the stone so you can explain a price change to your own customer.
- Test the coloured line in earrings and pendants before committing to rings, where wear risk is highest.
Care instructions worth printing on the card
Emerald and paraiba: warm water, mild soap, soft brush, no ultrasonic or steam. Ruby, sapphire and padparadscha: ultrasonic cleaning is acceptable; avoid sudden temperature change. All coloured stones: remove before swimming, cleaning with chemicals or heavy manual work. Printed care cards cost very little and materially reduce the returns that come from customers cleaning the wrong stone the wrong way.
Which coloured stones suit which product
Toughness, not only hardness, decides where a coloured stone can be set. Ruby and sapphire are corundum and suit rings, bracelets and pieces that see daily wear. Emerald and paraiba tourmaline are more fragile and are better placed in earrings, pendants and protected settings, where they are less likely to knock against a bench or a handbag. Padparadscha sapphire shares corundum durability and works in bridal pieces.
When you plan a collection, match the stone to the product before you match the colour. A bracelet run in emerald will see more setting and wear damage than the same run in sapphire, and that difference shows up as returns rather than as a stone quality problem.
Receiving and checking a coloured stone parcel
- Sort the parcel by size band first, then by colour on white paper under daylight and a colour-corrected lamp.
- Check each stone for eye-clean clarity and record any fracture filling, oiling or dyeing stated on the paperwork.
- Confirm the treatment status in writing, and keep the same status for any reorder six months later.
- Measure calibrated stones in tenths of a millimetre and reject mixed sizes that cannot be built into suites.
- Photograph the retained reference stones under two lighting conditions so future runs have a benchmark.
Coloured stone wholesale questions
Which coloured stones are available in calibrated sizes?
Emerald, ruby, sapphire, paraiba tourmaline, padparadscha sapphire and zircon are supplied in calibrated rounds, ovals, cushions and pears, with a tolerance in tenths of a millimetre. Loose melee is sorted into matched parcels by size band.
Are coloured stones treated, and is that disclosed?
Treatment varies by stone and must be stated on the invoice. We record whether material is as-grown, oiled, filled or dyed, and disclose the same status to your market; consistency of disclosure matters more than the absence of treatment.
What MOQ and lead time apply to coloured stone jewellery?
Finished coloured stone pieces start at MOQ 10 pcs, with a 12-18 day lead time after sample approval. Loose stone parcels are quoted per carat by size band and colour, and matched reorder stock is held where available.
Can I build a matched suite or bracelet run?
Yes, when you order calibrated sizes against a retained colour standard. Suites, halos, bracelets and earring pairs can be assembled from sorted stock rather than hand-sorting a mixed lot.
Natural versus lab grown coloured stones
Natural coloured stones vary in colour, clarity and size from parcel to parcel, and that variation is part of their appeal; pricing reflects rarity and treatment history. Lab grown ruby, sapphire and emerald offer tighter colour consistency, matched sizes and steadier per-carat pricing, which makes them easier to build into suites and repeat orders. Neither is a substitute for the other: choose natural where the customer wants origin and character, and choose lab grown where consistency, calibrated sizes and a stable reorder price matter.
Matching colours for a coordinated collection
A coordinated collection reads as one line when the stones share a colour band rather than a single exact shade. Pair warm reds with gold and cool blues with silver or white gold, and keep one dominant colour per look so the range does not look like a mixed lot. Order calibrated sizes against a retained reference stone, and photograph that reference under daylight and a colour-corrected lamp so the next run can match the same standard.
Earring pairs and matched suites should be ordered from the same sorted parcel, because stones taken from two different parcels can read as a mismatch even when both carry the same colour grade. Bracelets and halos need matched melee by size band, and that sort is easier to hold in stock when the first order specifies the size tolerance rather than a loose carat range.
Planning a coloured stone collection with our factory
Start with one or two stone types rather than a broad palette; depth in one look usually sells better than a shallow range across many colours. Fix a colour standard with a reference stone and two-light photographs, then order calibrated sizes so suites and pairs can be built from stock. Browse our loose lab grown gemstones and compare colours in the lab grown ruby and lab grown sapphire lines, or send your design to our trade desk for a wholesale quote.