How to buy a diamond online in Bangkok or anywhere else?


Buying a diamond online today has never been easier.  There are now multiple websites providing free access to diamond inventory search lists, actual GIA (or other certificate) copies for each choice and beautiful finished ring images.

Therefore, you can now just search and browse your ring choice and then buy with a simple click of a button your diamond and engagement /wedding ring.


So, now as we have all this information out there, why do we need to go to a jewelry store or trusted diamond wholesaler anymore?

For example, if the GIA certificate states that the diamond is 1.00 carat, H-color, VS1-clarity, excellent cut, excellent polish, excellent symmetry with no fluorescence, I know exactly what I am getting so the only thing I have to see is if I am getting the “BEST” price or deal, right?

Unfortunately, the above statement is NOT exactly true and there is definitely “more than meets the eye” when purchasing a diamond online or elsewhere.


Just because you have a certificate that states all the specifications, it doesn’t mean you have an excellent looking, premium cut, white & eye-clean looking diamond.

In this blog article I will discuss what we as dealers have to check when purchasing a diamond online or at any diamond office and I hope this helps you all when making your individual purchase choices.  


First thing you should always make sure when buying a diamond online is if it has a third party laboratory certification.  On the certification you will get all the important 4Cs parameters (carat weight, color, clarity and cut) which is very important in helping you determine what is the correct value of a diamond.

The best labs are AGS or GIA certificates then HRD, IGI and finally EGL (which I highly don’t recommend).  Please note that the lower certificates like HRD or IGI are considered less strict in their color grading and therefore sold a lot cheaper than GIA or AGS certificates.

For most certificates you can verify them by going to their websites and typing the certificate number and carat weight.   This process is called verifying your diamond report and I have provided links for each lab below.

Please ensure before making any purchase, to do this simple five seconds certification check to make sure the diamond you are getting is real and not forged.

Report Verification Links


Checking diamond online in Bangkok - GIA Laser inscription on the girdle of a diamond should match GIA certificate
Laser inscription on the girdle of a diamond should match GIA certificate

Another way to check if your diamond matches with the certificate is to check if it has a laser inscription.

Most GIA certified diamonds, both large and small, will have laser inscription on the girdle that matches the GIA certificate number.

This feature is also sometimes included in other labs (AGS, HRD, IGI) diamonds as well, though they are more common for larger size diamonds than smaller.


All certificates will have diamond carat weight written and if the certificate is real you can be sure the carat weight is accurate as well, as this is the easiest thing to check.  Carat weight can also be checked with a simple mettler which every wholesaler or retailer will have in their office or shop.


Color grading on the other hand is very subjective and this really depends on which lab the diamond has been certified.   In my experience, I found GIA or AGS labs to be the most accurate.  HRD and IGI are a little more lenient in the color grade and I usually find them one or two grades more ambitious than typical GIA or AGS.

There is one aspect in color which is NOT STATED in all diamond lab certificates which is very important to verify – what “color shade” a particular diamond is?

As wholesalers when we buy diamonds online, we always ask the diamond supplier or manufacturer if this diamond has no “BGM” – which means, has no brown, green or milky shade as all these are undesirable traits for overall diamond look.

Once a diamond is graded G-color or below, one can start noticing some color shade on the sides of the diamond which typically is yellow or brown.

In the trade, brown color shades are usually unattractive compared to yellow shades and therefore sold much cheaper.    Green shades are definitely unwanted and should be avoided completely.

Diamonds online in Bangkok - H-color diamonds should look white like this pair of GIA certified 3 carats diamond - H-color, VS1 & VS2 clarity.
H-color diamonds should look white like this pair of GIA certified 3 carats diamond – H-color, VS1 & VS2 clarity, triple excellent cut.

So, just because you have an “H-color” GIA certified diamond, it does not mean that all H-color diamonds are alike because they may have different color shades.

If your diamond is definitely white looking (with very, very little yellow tinge) this is the most desirable H-color diamond.


Clarity grading is also very subjective depending on the lab certifying the diamond.  Again GIA or AGS labs are the most accurate labs than HRD and IGI.   All labs provide diamond plot charts which allows you to see where the inclusions are located and what type of inclusions they are.

However, no two diamonds are alike especially for clarity grading and one VS2-clarity diamond might be better than other even though both are certified by GIA.   All lab certifications do not provide what color the inclusions are, which is actually another important factor we have to consider when buying any diamond.


When we wholesalers buy a diamond we always check if there are any “opaque” black or white inclusions, feathers or other prominent inclusions under the table of a diamond.

Black inclusions under the table are the most undesirable trait as they are usually visible to the naked eye.

Concentrated white inclusions or feathers also are sometimes noticeable. There also instances where crystal inclusions under the table is acceptable because the crystals are transparent and therefore not visible with naked eye.

So, just because a certificate has a plot chart with inclusions in the middle of the table doesn’t mean the diamond is bad.

This can only be judged by getting the information from the supplier or by looking at an actual diamond picture face-up.   Luckily most large manufacturers do provide us this information, but as an end-user one should also check these factors.

Diamond in Bangkok online - Actual GIA diamond plot chart for a F-color, VS2-clarity diamond
Actual GIA diamond plot chart for a F-color, VS2-clarity diamond which we sold to a client recently.  Even though couple of crystals are located in corner of the table, this diamond is still eye-clean.

An ideal VS2 diamond will be eye-clean and you will not be able to notice any inclusions until you check it under a microscope or 10x gem loupe.

You should also remember that no diamond inclusions are alike, so another way to check if the diamond you have is same as the one stated on the certificate is by matching it with diamond plot chart. 

On the plot chart it will indicate where the inclusions are located and the type of inclusions they are, so this should match with the diamond you are purchasing. 

IF IT DOES NOT MATCH, then you will know you are getting scammed! Please note, for GIA certificates below 1 carat, they will not include these diamond plot charts in the certificate and therefore, the only way to check is to see the laser inscription on the girdle.


This is one 4C which is very debatable and I can focus almost one whole blog post exclusively for this (maybe I will soon).

The most ideal cut diamonds are considered Triple Excellent cuts in GIA, HRD, IGI or Grade 0 in AGS.

Again how strict the cut grading is depends on which lab grades it.  In the trade, GIA and AGS both have strictest cut grade criteria but both have different ways in grading what “an excellent” cut grade is.


GIA believes the human eye takes priority over what the technology says while AGS believes more in technical numbers or images.   Therefore, for AGS labs, it is more important to have “the correct numbers” an ideal crown angle, girdle size, diamond depth, pavilion angle, etc.

This usually will result in ideal aset analysis, ideal scope images, diamxray analysis, etc.  So, shouldn’t these diamonds look great!  This is sadly, NOT true.

Buy diamond online in Bangkok - An ideal cut diamond should be bright, sparkle and have an amazing rainbow fire - like this ring we just made for our client which is a GIA triple excellent cut diamond center
An ideal cut diamond should be bright, sparkle and have an amazing rainbow fire, i.e. like this ring we just made for our client which is GIA certified triple excellent cut diamond center

After multiple studies by GIA, they have found that some diamonds which don’t have these ideal numbers or technical images do look great with human eye observations which should always take precedence over what technology has to say.

This is because in the end we the end-users are going to decide how the diamond looks with our eyes and not what the technical “computer” screen says.


So, how do we buy a diamond/s online without seeing it in person?  Big manufacturers do provide us wholesalers, the ideal aset, ideal scope, diamxray images, but in the end I always ask them, how does the luster look.

They will usually accurately describe the diamond as excellent, very good or good.  Therefore, you should only deal with people who you trust and provide you honest judgment in how the diamond looks before making your purchase online.

An ideal cut diamond should be bright, sparkle and have an amazing rainbow fire!


Fluorescence is another common trait of a diamond and a very debatable characteristic which everyone in the trade doesn’t agree with. In my experience, fluorescence doesn’t affect the overall look of a diamond and in fact makes diamond look whiter especially for H-color or lower color diamonds.

Fluorescence in some instances might make the diamond look “milky or cloudy” but again this occurs very rarely (0.01% of the time).  Because of this misconception these diamonds are usually sold at a discount.

We as dealers when buying fluorescence diamond online will always ask our supplier if a particular diamond has any milky or cloudy shade look.  If it does we won’t buy this diamond as it will hurt the overall look of a diamond.

If you want to read more about fluorescence and how it affects the overall look of the diamond, I will recommend checking the following links:



Buying a diamond online can be more tedious than one realizes and one should always remember that even though there is lot of information out there and a lot of technologically advanced images, in the end, it is most important to deal with people you can trust so they can answer all your questions regarding color, clarity, & cut accurately.

No technology can ever beat a human eye observation!

I hope the above guide is helpful and if you have any additional questions please feel free to provide your comments below or send me a message at


Thai Native Gems Diamond Search & Custom Engagement Ring service:

If you are in the market looking for the best diamond and custom hand made engagement ring.  Contact Us.  Let us know what your budget is and what you are looking for.

From this initial information, we will swiftly find and email you 4 to 5 center diamond options.  Unlike other traditional or online dealers, I am not looking to sell you anything. But will provide you honest, frank and objective opinion in what we think is best in the budget you offer.

This service is free, and there absolutely no commitment to buy any of our suggestions. The only thing you have to do is not respond to our email and you won’t hear from us again! So, you truly have nothing to lose!

How do we compile this diamond list?  Our search process is provided below:

1) We first will contact our local diamond supply network and check if there are any stones that fit your requirement in Bangkok. We have over 50 contacts in Bangkok and will check ALL to make sure we can provide you the best deal.

2) If not satisfied, we will then check online through our extensive global network sifting through over 900,000+ diamonds. and will find you the best diamond. The only setback when choosing the diamond from this global list is, it can take one to two weeks to arrive to Bangkok.

What type engagement rings can you make and how are they made?

1) We usually set our engagement rings in 18k yellow or white gold or 950 platinum settings.  Our rings are all hand-crafted and made by highly skilled Thai craftsmen.

Examples in some of the rings we made you can see on our YouTube channel and shown below:

YouTube Channel PLAY LIST

Contact us today to get all your wholesale gemstones, diamonds and jewelry needs.  We can Source, Search and Supply anything you require.   
What will you get if you contact us

  • Start a conversation with us at
  • Get wholesale and highly competitive prices of gemstones & diamonds from anywhere through our extensive network of contacts around the world
  • All stones sold by us is verified in house by our GIA Graduate Gemologist or certified
  • We provide personalized service and NOT the same old “One Size Fits All” Approach

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