Ruby
Ruby is the red variety of corundum, coloured by chromium, and by weight it is among the most valuable of all gemstones. The same mineral in any other colour is sapphire, so the boundary between a red ruby and a pink sapphire is a nomenclature question with a very large price attached. It is a hard and tough stone, second only to diamond in scratch resistance, which makes it as suitable for daily wear jewellery as it is for high jewellery and auction goods, and corundum in non gem grades also serves as an industrial abrasive and bearing material.
Listed ruby markets
Each line is a grade at a delivery point. Open one for its full specification and terms.
Grades
Ruby is bought on colour, and every other term is a modifier on the colour. The contract fixes the species and variety, the colour description, the treatment disclosure, and where commissioned the laboratory origin opinion, because origin carries a real premium in this stone.
Species, variety and identification
9 grades
| Grade | Definition |
|---|---|
| SpeciesCorundum, confirmed by gemmological testing | Confirmed against the constants of corundum, refractive index, birefringence and specific gravity. |
| VarietyRuby | Red corundum. Where the colour falls short of red the correct name is pink sapphire, and the nomenclature standard governs which name may be invoiced. |
| Colouring elementChromium, with iron as a modifier | Chromium gives the red and the fluorescence. Iron suppresses the fluorescence, which is why iron poor material reads brighter. |
| Refractive indexReported, with the birefringence | Measured on a refractometer, separating corundum from spinel, garnet and the red imitations. |
| Specific gravityReported | Measured hydrostatically, confirming the species. |
| HardnessReported on the Mohs scale | Corundum is second only to diamond, which is what makes ruby a daily wear stone and non gem corundum an abrasive. |
| FluorescenceDescribed, under long and short wave ultraviolet | Chromium fluorescence adds to the face up red in daylight. Its strength is an identification, origin and value indicator. |
| PleochroismDeclared, as the two observed colours | Corundum is dichroic. Orientation of the table decides the face up colour and is a cutting instruction. |
| Optical phenomenaDeclared, where present | Asterism from oriented rutile needles, producing a star ruby, which is a separate product cut as a cabochon. |
Colour
6 grades
| Grade | Definition |
|---|---|
| HueDescribed, from red to purplish red to orangey red | The primary hue with any modifier named. Pure red to slightly purplish red is the classic description of the finest material. |
| ToneDescribed, from light to dark | Medium to medium dark tone holds the saturation without going flat. |
| SaturationDescribed, from weak to vivid | The dominant value term. Vivid saturation with strong fluorescence is what the trade is paying for. |
| Colour zoningDescribed, by location and intensity | Corundum grows in colour bands and the zoning decides orientation, yield and how evenly the finished stone reads. |
| Fluorescence contributionDescribed | How much the chromium fluorescence adds to the face up colour under daylight, which is part of why iron content matters commercially. |
| Lighting conditionDeclared | Assessed under daylight equivalent lighting, with the incandescent appearance noted. |
Clarity and inclusions
6 grades
| Grade | Definition |
|---|---|
| Clarity typeType two, under the standard clarity classification | Ruby is expected to carry inclusions and is graded against that expectation, so an eye clean stone of size is exceptional. |
| Inclusion suiteDescribed | Rutile silk, crystals, fingerprints, healed fissures and growth structures. The suite is the primary evidence in a laboratory origin opinion and in separating natural from synthetic. |
| SilkDescribed, by density and orientation | Rutile needles. Light silk can improve the face up glow, heavy silk mutes the stone, and the presence of undamaged silk indicates the material has not been heated. |
| Fractures reaching the surfaceDescribed, by count, position and reach | The breaks that take a filler and the breaks that threaten durability. |
| Eye clean assessmentDeclared, at the stated viewing distance | The working commercial threshold. |
| TransparencyDescribed, from transparent to translucent | Transparent faceting material, translucent star and cabochon material, and opaque carving material are separate products. |
Rough form, size and yield
6 grades
| Grade | Definition |
|---|---|
| Rough weightCarats, per piece and per parcel | Weighed on a calibrated balance, with the piece weights listed for significant stones. |
| DimensionsMillimetres, length by width by depth | Measured on the crystal or preform, because the finished dimensions decide what the stone can be set into. |
| Estimated yieldPercentage of rough weight, declared as an assessment | Corundum is dense and colour zoned, so the yield assessment carries real weight. It is an opinion, not a warranty. |
| Shape and formDeclared, as crystal, water worn pebble, cobbed piece or preform | Barrel and tabular crystals from hard rock, water worn pebbles from alluvial workings. |
| OrientationDeclared | Where the table sits relative to the optic axis, which governs face up colour in a dichroic stone and the star in a cabochon. |
| Size distributionDeclared, as the count within each stated weight band | For a sorted parcel, the distribution across sizes. |
Treatment and disclosure
7 grades
| Grade | Definition |
|---|---|
| Heat treatmentDisclosed, as heated or unheated, with the temperature range indicated | Heating dissolves silk and improves clarity and colour. It is permanent, accepted and near universal, and unheated material with a laboratory report carries a large premium. |
| Flux assisted healingDisclosed, with the residue described | Heating with a flux that heals fractures and leaves residue in them. It is a more intrusive treatment than plain heat and is disclosed separately. |
| Lead glass fillingDisclosed, with the extent stated | Filling of heavily fractured material with high refractive index lead glass. It is not durable to ordinary jewellery repair and it must be disclosed in full and priced as a separate product. |
| Diffusion treatmentDisclosed, with the element named | Surface or lattice diffusion of colouring elements, disclosed with the process and the depth of the colour layer. |
| Dyeing and fracture fillingDisclosed, with the substance identified | Any oil, resin or dye, with the extent and the position stated. |
| Synthetic screeningDeclared, against the named laboratory method | Confirmation that the stone is natural corundum rather than flame fusion, flux grown or hydrothermal synthetic ruby, all of which are produced in volume. |
| Disclosure recordDocument, per stone or per parcel | The written treatment disclosure on the invoice and with the parcel. |
Parcel, documentation and settlement
9 grades
| Grade | Definition |
|---|---|
| Parcel compositionDeclared, by piece count and total carat weight | What is actually in the lot. A rough parcel is sold as a parcel, so the count, the weight and the size distribution are the contract. |
| Weight basisCarats, to the stated decimal place | Weighed on a calibrated balance, with the weighing certificate and the tolerance named. |
| Sealing and markingDeclared | Parcels sealed in the presence of both parties or their agents, numbered and photographed, so the goods that arrive are the goods that were inspected. |
| Laboratory reportDocument, per stone or per parcel | Issued by a named laboratory operating to the international testing competence standard, covering species, treatment and, where commissioned, origin. |
| Origin determinationDeclared, where commissioned | A laboratory origin opinion is an opinion based on inclusion suites and trace element chemistry. It is stated as such and never as a guarantee. |
| Export and import documentationDeclared | Export permit or certificate from the producing country, customs classification under the harmonized system, and any royalty or clearance certificate the origin requires. |
| Responsible sourcingDeclared | Mine or source, chain of custody, and the due diligence statement, including artisanal and small scale mining status where it applies. |
| Viewing and rejectionDeclared | Where and when the buyer may view, the memo or consignment terms if any, and the window and grounds for rejection after the laboratory report. |
| Insurance and carriageDeclared | Valuation for transit, the specialist carrier or secure courier named, and the point at which risk passes. |
Grades outside this list trade on request. Send us the contract specification you work to and we will price against it.
Locations
| Country | Region | We trade it as |
|---|---|---|
| Myanmar | Southeast Asia | Origin and destination |
| Mozambique | Southern Africa | Origin and destination |
| Madagascar | Southern Africa | Origin and destination |
| Tanzania | East Africa | Origin and destination |
| Kenya | East Africa | Origin and destination |
| Malawi | Southern Africa | Origin and destination |
| Zimbabwe | Southern Africa | Origin and destination |
| Ethiopia | East Africa | Origin and destination |
| Viet Nam | Southeast Asia | Origin and destination |
| Thailand | Southeast Asia | Cutting, treatment and trading centre |
| Cambodia | Southeast Asia | Origin and destination |
| Sri Lanka | South Asia | Origin and destination |
| Afghanistan | Central Asia | Origin and destination |
| Pakistan | South Asia | Origin and destination |
| Nepal | South Asia | Origin and destination |
| India | South Asia | Cutting and trading centre |
| China | East Asia | Cutting centre and destination |
| Australia | Oceania | Origin and destination |
| Greenland | Arctic | Origin and destination |
| United States | North America | Origin and destination |
| Brazil | South America | Origin and destination |
| Tajikistan | Central Asia | Origin and destination |
| Russian Federation | Eurasia | Origin and destination |
| Israel | Middle East | Cutting and trading centre |
| United Arab Emirates | Middle East | Trading hub and free zone |
| Switzerland | Europe | Trading, laboratory and vaulting centre |
| Belgium | Europe | Trading centre |
| Germany | Europe | Cutting centre and destination |
| United Kingdom | Europe | Trading centre and destination |
| France | Europe | Destination |
| Italy | Europe | Destination |
| Spain | Europe | Destination |
| Hong Kong | East Asia | Trading centre |
| Singapore | Southeast Asia | Trading and finance |
| Japan | East Asia | Destination |
| Republic of Korea | East Asia | Destination |
| Turkey | Western Asia | Origin and destination |
| Saudi Arabia | Middle East | Destination |
| Nigeria | West Africa | Origin and destination |
Origins and destinations outside this list trade on request. We are not limited to the locations shown here.
Timing
Production is when the stone comes out of the ground at origin, which follows the mining season, the water level at an alluvial working and the rhythm of artisanal digging rather than a crop calendar. Arrival is when material from that origin typically reaches a cutting or trading centre. The gap between them is sorting, export clearance and the journey to the market.
HarvestArrival
| Origin | J | F | M | A | M | J | J | A | S | O | N | D | Window |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Myanmar | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecThe historic benchmark, from Mogok and Mong Hsu. Mogok material sets the colour reference the trade quotes against, and export documentation and sanctions position must be established before any commitment. |
| Mozambique | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest May to Oct, arrival Jul to DecThe dominant modern source, from the Montepuez area, with large scale mechanised production and regular tendered auctions, weighted to the dry season. | ||||
| Madagascar | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest Apr to Oct, arrival Jun to DecAlluvial and hard rock production from the southern and eastern workings, accessible in the dry season. | |||
| Tanzania | Arrival | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Harvest Jun to Nov, arrival Aug to JanWinza and Longido production, weighted to the dry months. | ||||
| Kenya | Arrival | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Harvest Jun to Nov, arrival Aug to JanProduction from the John Saul and Baringo areas, mined through the drier season. | ||||
| Vietnam | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest Mar to Sep, arrival May to NovLuc Yen and Quy Chau material, with the workings following the dry months. | |||
| Thailand | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecHistoric Chanthaburi production is largely worked out, but Thailand remains the principal heating, cutting and trading centre and ships year round. |
| Sri Lanka | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecAlluvial gem gravels producing pink to red corundum year round, with the pace set by the water in the pits. |
| Afghanistan | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest May to Sep, arrival Jul to NovJegdalek production, moving out overland once the passes open. |
Windows outside this pattern trade on request, including forward commitments against a mine run, parcels already sitting in a cutting centre, and material held in a free trade zone or bonded vault.
Customs, packing and contract terms
Indicative terms for ruby. Tariff classification is the importer’s responsibility and limits change, so confirm both against the destination customs authority and the current regulation before you fix a contract.
- HS heading7103.10 Precious stones, unworked or simply sawn or roughly shaped
7103.91 Rubies, sapphires and emeralds, otherwise worked - PackingSealed and numbered parcels under a valuation certificate. Never containerised.
- Container loadingNot containerised. Moves by insured secure courier or hand carry against a declared valuation, with customs presentation at both ends.
- Contract and arbitrationCIBJO Blue Book nomenclature, with a GIA, Gubelin or SSEF report where the value warrants it. Sale on viewed and approved parcel terms with weight and treatment disclosure. Arbitration under the rules of the World Federation of Diamond Bourses or the ICC.
- Destination limitsUS OFAC sanctions and the JADE Act prohibit import of Burmese origin ruby into the United States, including material cut in a third country, so origin evidence by an accredited laboratory is a condition of sale. CIBJO treatment disclosure covers heat, lead glass filling and diffusion, and anti money laundering registration applies to dealers in precious stones.
Common questions
What grades of ruby does SIP Global trade?
We quote 43 published grades of ruby, including Species - Corundum, confirmed by gemmological testing, Variety - Ruby, Colouring element - Chromium, with iron as a modifier, Refractive index - Reported, with the birefringence, Specific gravity - Reported and Hardness - Reported on the Mohs scale. Every grade is tied to a delivery point and a settlement route. Grades outside the published list are priced on request.
How is ruby graded?
Ruby is bought on colour, and every other term is a modifier on the colour. The contract fixes the species and variety, the colour description, the treatment disclosure, and where commissioned the laboratory origin opinion, because origin carries a real premium in this stone. Grading runs on 6 systems: Species, variety and identification, Colour, Clarity and inclusions, Rough form, size and yield, Treatment and disclosure and Parcel, documentation and settlement.
Where does SIP Global trade ruby?
We trade ruby in Myanmar, Mozambique, Madagascar, Tanzania, Kenya, Malawi, Zimbabwe and Ethiopia and 31 further markets. Origins and destinations outside this list trade on request. We are not limited to the locations shown.
When is ruby harvested and when does it arrive?
Typical windows are Myanmar: harvest jan to dec, arrival jan to dec; Mozambique: harvest may to oct, arrival jul to dec; Madagascar: harvest apr to oct, arrival jun to dec; Tanzania: harvest jun to nov, arrival aug to jan; Kenya: harvest jun to nov, arrival aug to jan. Harvest is when the lot is taken at origin, arrival is when a shipment from that origin lands in a consuming market. Windows outside this pattern, including carry, trade on request.
What is the HS code for ruby?
Ruby is normally classified under HS 7103.10 (precious stones, unworked or simply sawn or roughly shaped) and HS 7103.91 (rubies, sapphires and emeralds, otherwise worked). The heading follows the form the goods are in at the border, and national tariffs extend it beyond six digits, so confirm the full line with the destination customs authority before you fix a contract.
How do I get a price for ruby?
Send the grade, the origin and the delivery window to the SIP Global desk. That is enough for a trader to come back with a level and a settlement route. 1 listed ruby market is published on this page, each with its full specification and terms. We take both sides, physical and financial, prompt to long dated.
Standards and data sources
The grading language on this sheet follows published standards. Trade volumes and tariff lines are public record. Verify anything here against the source.
- UN ComtradeOfficial international trade statistics by HS code
- ITC Trade MapBilateral trade flows and tariff data
- FAOSTATFAO production and trade series for agricultural commodities
Price this with our desk
Grade, origin and window if you have them. If what you are carrying does not fit the sheet above, describe it in your own words and a trader will take it from there.