Home Diamonds Diamond Identification Made Simple

Diamond Identification Made Simple


Diamond Identification Made Simple

Diamond is perhaps one of the easiest stone to identify.  There are many physical properties of diamonds that are unique by itself and these characteristics are not found in other colored stones.

Care must be taken that a synthetic diamond will also pass these tests.  Synthetic diamonds have the same properties as natural diamonds except that they are grown in laboratories using various highly technical methods.

The Refractive Index (Read here for RI) is 2.417.  This is perhaps one of the highest RI found among gemstones.  But RI is never used for identification of diamond as the normal gemological laboratory Refractometer does not read beyond 1.80.

The Specific Gravity (Read here for SG) is 3.52 and because cut diamond is very small in nature (a 5ct or 1gm diamond is considered quite big) SG testing is never used.

No See-Through Of A Diamond
Faceted Cut Quartz With See Through

As diamond has a very high RI, when you place a Round Brilliant Cut Diamond onto a pencil drawn line or some typed words, there is a no see-through effect, that is, you cannot see the line or the words inside the diamond.  In fact this is a quick and dirty test for diamond identification as you can do it everywhere.

Frosted Girdle On A Diamond

Most diamonds have a frosted girdle not found in any colored stones.  Cutters normally will leave the girdle frosted in order that this can be identified as a diamond easily. However, some of the girdles are polished, so if you have a polished girdle you cannot jump to conclusion that this is not a diamond.

Sharp Facet Junctions In A Diamond

As diamond is the hardest mineral (Read here for Mohs hardness) hence, it has very sharp facet junctions.  If you see a lot of tiny fractures along the faceted junctions of a colorless stone, it is not likely a diamond.

Fractures In A Diamond Is Step-Like

The way a diamond or a colored stone fractures can give a lot of information on the identity of the stone.  Diamond is the only stone that has a step-like fracture.  (compared this to glass where the fracture is conchoidal, meaning curve-like).  If you have a cut diamond and there is a sizeable fracture on it, use a loupe (Read here on how to use a loupe) to view the fracture surface carefully.  It is likely that you will see the step-like fracture.

Beardings On The Girdle Of A Diamond

Most diamonds have tiny root-like tendrils protruding perpendicular to the girdle which are called beardings.  However, in very well cut diamonds you may not find any of these beardings.  If you have beardings then the specimen stone is a diamond.

Trigons Are Natural Indentations On A Diamond

Trigons are minute triangle-like crystal indentations on a rough diamond.  Most cutters will try to retain these trigons on the side of the girdle.  But these are rare and the price of a particular diamond with trigons on the girdle have a very high premium.

A Diamond Tester Is A Convenient Tool

And of course a diamond tester is the easiest way to identify a diamond.  Diamond is a very good conductor of heat.  When a diamond tester is switched on, the probe will heat up and when it touches a diamond the heat is conducted away quickly which will be indicated with a small high pitched sound and normally a green indicator will alight.  Other stones will not respond to this test.  However, Mossainite, a type of synthetic stone, will respond positively to this test and you have to separate it between the two.  (This will be dealt with in a future post).

Good luck to you.

Photo courtesy:

http://www.jogiadiamonds.com.au, http://www.professionaljeweler.com, http://www.diamondvues.com, http://www.kristallsmolensk.com, http://www.thelittlecameras.com, http://slwa.files.wordpress.com, http://www.jewelinfo4u.com, http://www.gemnation.com, http://www.gemnation.com, http://www.bwsmigel.info/,http://www.jewellerycatalogue.co.uk/http://www.moregems.com, http://www.capewatch.co.za, http://pursuitist.com, http://gia.edu, http://www.birdamlasu.com,

Previous articleU Hmat – The Ruby King
Next articleThe Modern Day Gold Rush
I am a Graduate Gemologist trained at the Gemological Institute of America (GIA) in New York City, USA. I hold an MBA degree from Cranfield University, United Kingdom, and a Bachelor degree in Mathematics. My earlier profession was a banker until I found jade in Myanmar (Burma) in the early 90s. I have traveled to the fabled Hpakan Jade mines, and Mogok, the world’s famous rubies and sapphires mines in upper Burma, with my second son. Three of my children are also Graduate Gemologist, GIA, NYC and they deal in diamonds, gemstones and jade. 我是在美国纽约市的美国宝石学院(GIA)接受过培训的宝石研究学家。 我拥有英国克兰菲尔德大学的工商管理硕士学位和数学学士学位。我以前的职业是银行家,直到90年代初我在缅甸接触到玉石。我曾经和我的次子一起去过缅甸上流传说中的哈帕翡翠矿山和莫谷矿山, 莫谷矿山是世界上著名的红宝石和蓝宝石矿山。我的三个孩子都是纽约市GIA毕业的宝石研究学家, 他们专门处理钻石,宝石和玉石.


  1. It’s rare for me to find something on the web that is as entertaining and fascinating as what you’ve got here. Your page is sweet, your graphics are outstanding, and what’s more, you use source that are relevant to what you’re talking about. You’re certainly one in a million, keep up the good work!

  2. Fine post. I learn something new on different blogs everyday. It is recommended stimulating to read content from other writers and learn a little something through. I’d love to apply certain on this content on my blog within the don’t mind. Natually I’ll make a link to a site. Thanks sharing.

  3. This a little bit funny. I found your site via search engine a few moment ago, and luckily, this is the only information I was looking for the last hours. I wrote two or three stories a day on the different sports teams, and pretty soon, it was as if the site was taking care of itself.

  4. OMG! It is like you understand my mind! You seem to know so much about this, like you wrote the book in it or something. I think that you could do with some pics to drive the content home a bit, but other than that, this is wonderful blog post. A wonderful read. I will definitely revisit again.

  5. I found your weblog on google and check several of the early posts. Preserve up the excellent operate. I just additional up your RSS feed to my MSN News Reader. Seeking forward to reading through additional from you later on!…

  6. Hey, just wanting round some blogs, appears a fairly nice platform you might be using. I am at present utilizing WordPress for just a few of my sites however trying to change one in every of them over to a platform much like yours as a trial run. Anything in particular you would suggest about it?

  7. Youre so cool! I dont think Ive read anything like this before. So nice to find somebody with some original thoughts on this subject. realy thank you for starting this up. this blog is something that is needed on the web, someone with a little originality. good job for bringing something new to the internet!

  8. I became just browsing here and there but got to read this post. I have to admit that we’re from the hand of luck today or else getting this kind of excellent post to learn to read wouldn’t are already achievable to me, no less than. Really appreciate your articles.

  9. Excellent post! I?michael just starting out in neighborhood management/marketing media and trying to understand how to do it well – resources like this post are incredibly useful. As our organization is based in the US, this?s all a little new to us. The actual example above is one thing that I worry about too, how to show your personal genuine enthusiasm as well as share the fact that your products is useful in that case Adauga Anunturi Gratuite Bacau

Comments are closed.