Should a Colored Gemstone Be Sent to a Laboratory?
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The direct answer is that most colored gemstones are not economically worthy of a major laboratory report.
That does not mean they are fake. It means the likely commercial value of the stone does not justify the combined cost, shipping, insurance, risk and time required to obtain the report.
A laboratory report makes sense when the answers could materially change how the stone is understood or sold. It should not be ordered merely because a report feels more official.
The Market Contains Natural, Synthetic and Treated Stones
Low-cost synthetic colored stones are abundant. Some are straightforward to identify, while others require advanced testing. The presence of synthetic material makes reliable identification important, but it does not make laboratory testing economical for every inexpensive stone.
Treatment is also common in significant parts of the natural-gemstone market.
GIA reports that most ruby has been heated. It also states that a large amount of sapphire on the market has been treated by heat or lattice diffusion. Filling surface-reaching fractures with oil, resin or wax is a common clarity treatment for emerald.
These statements apply to particular gemstone varieties. They should not be expanded into a claim that every natural colored stone, or most stones of every species, are treated.
Treatment does not automatically make a gemstone undesirable. It changes how the stone must be described and can materially affect value.
What a Report Can Establish
Depending on the laboratory and service selected, a colored-stone report may address:
- The identity of the material
- Whether it is natural or laboratory-created
- Detectable treatments
- Weight and measurements
- Color description
- An opinion concerning geographic origin for eligible varieties
- A photograph of the submitted gemstone
GIA explains that its Colored Stone Identification Report identifies the material, states whether it is natural or synthetic and lists detectable treatments. Its Identification and Origin Report adds an origin opinion for specified gemstone varieties. Review GIA's colored-stone report services.
A report does not determine beauty, desirability or market value.
Most Ordinary Stones Do Not Need One
A major laboratory report may not make economic sense when:
- The stone has limited expected value
- It is a small commercial gemstone
- The report cost represents a significant part of its value
- Geographic origin would not affect the transaction
- The stone has visible damage or limited marketability
- It belongs to an ordinary mixed parcel
- The likely result would not change how the stone is sold
Submitting a $100 stone for several hundred dollars of testing does not transform it into a more valuable gemstone. It produces an expensive document attached to the same stone.
When Testing Becomes Important
A major report may be justified when the stone is represented as:
- An important natural ruby, sapphire or emerald
- Untreated or showing no evidence of heat
- Originating from a source that receives a recognized market premium
- An important natural alexandrite, jadeite, spinel or Paraíba-type tourmaline
- A natural stone that could be confused with a synthetic or composite
- A gemstone whose treatment level could materially affect value
- A stone being prepared for a substantial retail or auction transaction
The guiding question is not whether a report would be interesting. It is whether the answer could change the stone's commercial category enough to justify obtaining it.
Start With Professional Screening
A knowledgeable gemstone dealer can often determine whether a stone warrants more advanced laboratory work. This initial screening is not a substitute for a laboratory conclusion. It is a way to avoid spending major-laboratory fees on every stone in a mixed collection.
The dealer may recommend:
- No report
- Basic identification
- Treatment testing
- A complete identification report
- Identification and geographic-origin analysis
- A second laboratory opinion for an exceptional stone
The appropriate choice depends on the stone and the question that needs to be answered.
Who Pays for the Report?
A seller may obtain a report before offering the gemstone. The seller then accepts the expense and the possibility that the result will not support the expected description.
A dealer may purchase the stone with its uncertainty reflected in the offer, make the transaction conditional on testing or agree to submit it under separately stated terms.
Before submission, the parties should establish:
- Which laboratory will be used
- Which report will be ordered
- Who pays the laboratory and shipping costs
- Who carries the risk during transportation
- What happens if the conclusion differs from expectations
- Who owns the report if the transaction does not close
A laboratory report should answer a commercially important question. It should not be used as decoration.
For private access to individual natural colored stones, enter The Stone Room. To discuss building a custom piece around a selected gemstone, visit The Bench.
Laboratory conclusions apply only to the gemstone examined and depend on the testing performed and the laboratory's available reference data. A report is not an appraisal, purchase offer or guarantee of value.