What is a gemstone 'certificate' or laboratory report?

What is a gemstone laboratory report or ‘certificate’?

Have you often heard Jewellers call their diamonds 'GIA-certified' and wondered what that actually means? Perhaps you had the choice between a 'certified' or 'non-certified' stone when designing a piece of custom jewellery. This blog post aims to reduce some of the confusion about gemstone 'certificates' and laboratory reports, to make your gemstone buying experience easier. 

A gemstone laboratory report is a document which provides identifying information about a gemstone, that can only be determined by a trained Gemmologist. They are often called ‘certificates’ but this is misleading, as laboratory reports do not provide any certification or warranty under any schemes. They are simply a document that contains a scientific assessment of a gemstone’s qualities.

Gemstone laboratory reports are not mandatory in the industry. Some Sellers will purchase them for high value gemstones to reassure customers that their product is as they describe. Customer’s may also request a Seller to purchase one for this purpose. Specialty gemstone supplies, such as Argyle Diamonds in Australia, may provide their own identification schemes for the purpose of establishing provenance for their gemstones (more on that below).

Every reputable laboratory report should contain some basic information:

Report Item

Why it is important

A gemstone identification number to match laboratory records

To demonstrate that the lab has given you the correct results and not mixed your stone up with another customer’s stone

The gemstone family (or type) and variety, for example ‘Quartz, variety amethyst’

Different gemstones may look the same but have very different prices. A report will confirm that you are buying the stone type that was described by the seller

The colour of the gemstone

To confirm that they have assessed the correct stone

The weight of the stone in carats, often written as ‘ct’

To confirm that they have assessed the correct stone

A clear, identifying photograph of the gemstone

To confirm that they have assessed the correct stone

Whether the lab has identified that gemstone as ‘natural’ or ‘synthetic/lab-created’

The price difference between the natural or earth-mined stones, and laboratory created stones, is significant. It is important to understand which type you are purchasing.

Any limitations to the report

If the laboratory is unsure about a gemstone characteristic or lacks the required equipment, knowledge or experience to make a clear decision regarding a gemstone characteristic, it needs to be made clear in their report


Depending upon the laboratory and the type of report that you have purchased, the report may also contain the following information:

Report Item

Why it is important

The origin of the gemstone: this is where the gemstone was mined from the earth


This is not always important to customers. There are two main reasons to be interested in origin:

1. To ensure the stone has been mined ethically

2. For some stones, such as sapphires and emeralds, ‘provenance’ or where the stone came from, can affect their price

Treatments: this is whether the laboratory has detected any human interference to the stone, generally aimed at enhancing the stone’s appearance


Treatments almost always affect the price of gemstones. Some treatments are common and widely accepted in the industry, such as heat treatment to sapphires. If the treatment is detected by the Seller or the lab it must ALWAYS be disclosed to the customer

Inclusions: these are naturally occurring characteristics of the stone.

Inclusions can occur inside the stone or on the stones’ surface. They can be minor such as little tiny crystals inside, or major such as large internal fractures which could undermine the structure of the gemstone and make it difficult to put into jewellery. It is important to understand the level of inclusions in your stone as they may affect its value.


What does a gemstone laboratory report look like?

A gemstone laboratory report can come in many formats. It may be as small as a business card or a larger fold-out pamphlet. It may be printed on standard paper, a glossy paper or on a plastic card. It may or may not contain a security seal particular to that laboratory.

Can I go to any gem lab?

It is important to understand that not all gemstone laboratories are created equally. Not all laboratories have hi-tech equipment and/or highly experienced staff. Some gemstone treatments can only be detected by specialised gemmological equipment. It is important to know what information you are seeking (see table above) and whether the laboratory you are approaching has the equipment, knowledge and experience to give you the correct identification.

Some well-known international laboratories are the GIA (Gemmological Institute of America) and HRD. You will see that many diamonds carry these reports due to the fact that diamonds have very specific grading criteria.

Two key gem laboratories in Australia that we recommend are:

Do I always need a laboratory report for my gemstone?

The short answer is no. If you are buying a coloured gemstone from a reputable dealer with experience in identifying gemstones, you may not need a gemstone lab report. Testing has generally already been carried out prior to the gemstone being listed for sale. Coloured stones also do not follow a single grading system. Therefore, gem labs have different ways of categorising the quality of coloured gemstones and do not always agree. 

However, diamonds are a different story. Diamonds go through international grading systems that relate very closely to their value. In order to understand the quality of the diamond you have purchased, you need to understand how it has been graded. GIA is the most commonly used grading system and uses measurements on scales of colour, carat weights, clarity and cut (known as 'the four Cs'). 

An added advantage of having a gemstone laboratory report, is for insurance purposes. You may be able to find a lab that employs a Valuer and can complete a full assessment for you that can be submitted to your insurance company to cover your treasure. 

Do gemstones from Amara come with lab reports?

Here at Amara Gemstones, we have standard gemmological equipment to test our stones and Julia Morganite is a qualified Gemmologist and Diamond Technologist. However, we do not have a full lab with high tech equipment. For this reason, we do not supply lab reports with all our stones.

However, there are two occasions when we send gemstones for laboratory reports:

  • When a gemstone characteristic is outside our ability to detect and we need to disclose this to our customers. We ask one of our lab partners to undertake this testing prior to listing the gem for sale and sell the gemstone with its report, as a package.
  • When our customers specifically request one, we are more than happy to use one of Australia’s two premiere gemstone laboratories at an additional cost.

 Still not sure if you need a lab report?

If you would to chat further about gemstone laboratory reports, please email Julia on info@amaragemstones.com. We can organise a time to chat more on this great topic!