Category Archives: Diamond Education

Clarity Enhancement of Diamonds – Part 1 – Laser Drilling

 

diamond-education-titlesmall

Hi Again,
I am going to discuss the important subject of Clarity Enhancement of Diamonds. It is a long but important discussion and well worth your time to educate yourself on this issue.

The clarity, or purity, of a diamond — the relative or apparent severity of flaws within the stone — has, like the other “four Cs”, a strong bearing on the evaluation of a diamond’s worth. The most common flaws, or inclusions, seen in diamonds are fractures (commonly called feathers, due to their feathery whitish appearance), and solid foreign crystals within the diamond; such as garnet, diopside, carbon or even other diamonds. The size, color, and position of inclusions can reduce the value of a diamond, especially when other gemological characteristics are good. Those who prepare diamonds for sale sometimes choose to reduce the visual impact of inclusions through oe or more of a variety of treatments.

This discussion will focus on the two major forms of “enhancements:” Laser Drilling and Fracture Filling. There is a big difference between these two methods of improving the look of a diamond as will be described. In this post I will discuss Laser Drilling of Diamonds. In my next post, I will discuss Fracture Filling of Diamonds.

Laser Drilling of Diamonds

The development of laser drilling techniques on a microscopic scale, has enabled diamond manufacturers and cutters to selectively target and either remove or significantly reduce the visibility of crystal or iron oxide-stained fracture inclusions. Diamonds have been laser-drilled since at least the mid-1980s. Most often it is used to whiten a black carbon crystal which is prominently visible in the diamond to the naked eye. Since the development of the laser drilling technique, and until more recently, laser drilling was an accepted part of the diamond manufacturing process. It is still used today on diamonds which have a significant presence of black carbon crystals imbedded in the diamond.

The drilling process involves the use of an infrared laser to bore very fine holes, or tubes, into a diamond to create a route of access to an inclusion. Once the included crystal has been reached by the drill, the diamond is immersed in sulfuric acid and the acid travels down the tube to dissolve the carbon crystal or iron oxide staining.

Several inclusions can be thus removed from the same diamond, and under microscopic inspection the fine bore holes are readily detectable, usually when the diamond is viewed from the side or bottom of the diamond.

Unlike fracture-filling (to be described in my next post), a laser drill hole is considered by the Gemological Institute of America’s Diamond Trade Laboratory to be an internal inclusion which is marked on their certificates just like other inclusions such as feathers, clouds and crystals. This is because the process of laser-drilling is a permanent process. In contrast to fracture-filled diamonds, the GIA does issue their certificates (called “Diamond Grading Reports”) for diamonds which have laser drill holes in them. The following is a direct quotation from GIA’s website concerning the range of diamonds for which the GIA Laboratory will and will not issue certificates.  

“GIA Diamond Grading Reports are not issued for synthetics, simulants, mounted diamonds or those that have undergone unstable treatments, such as fracture filling or coating. And while reports may be issued for diamonds that have been laser drilled or HPHT* processed, these stable treatments are prominently disclosed on the report.” [Emphasis added] *HPHT is a synthetic process designed to artificially improve the color of a diamond.

A diamond which is certified but which has a laser drill hole as one of its inclusions is not as valuable as another diamond of the same grade which does not have a laser drill hole. At A. Fishman & Son, we do not sell diamonds with laser drill holes.

My next post will cover Fracture Filling enhancements, a much more controversial method of enhancement, and what you, a diamond purchaser, should do when you go to buy a diamond.

So, in the meantime, until next time, Mind Your Diamonds!

Josh Fishman

www.afishman.com

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What Makes a Diamond Pretty – Part 4

 

diamond-education-titlesmall

Hi again,

Let’s continue our discussion about what makes a diamond pretty.  Again, a Pretty Diamond is not a scientific definition, it is a collection of factors which make a diamond worth owning. 

4. There are other characteristics which cause a diamond to appear to be priced as a “bargain” but which are undesirable.  For example, some diamonds which  have great “labels” are also undesirable because of their medium, strong or very strong fluorescence.  Stay away from these diamonds.  They will be undesirable in the future if you ever want to trade in the diamond.  Other diamonds are undesirable because of significant extra facets or naturals.  The polish and symmetry and cut grades of such diamonds can be “labeled” very good or even excellent and still have these characteristics.  You can’t tell from the certificate.  You have to speak to someone who can look at the diamond for you and tell you about it. 

So, let’s recap the four major factors that contribute to making a diamond “pretty;” that is, a diamond worth owning and putting your money into.

1. The diamond has to have a dimension that is appropriate for its weight;

2. The diamond has to have full brilliance;

3. The nature of the inculsions in the diamond has to be pleasing under magnification; and

4. There are other characteristics, such as strong fluorescence, which cause a diamond to appear to be priced as a “bargain” but which are undesirable. 

There are also some diamonds which have been “enhanced” to make them appear to the eye as better than they really are. In my next post, I will discuss the two primarily forms of “enhancements” which make a diamond very undesirable but which may make them appear to be very inexpensive for their grades.  These enhancements are very different from each other and shouldn’t be confused:  (1) laser drilling of certain types of inclusions, and (2) fracture filling open fissures in a diamond.  More on this important issue to come.

In the meantime, until next time, Mind Your Diamonds!

Josh Fishman

josh@afishman.com

www.afishman.com  

What Makes a Diamond Pretty – Part 3

 

diamond-education-titlesmall

Hi again,

Let’s continue our discussion about what makes a diamond pretty.  Again, a Pretty Diamond is not a scientific definition, it is a collection of factors which make a diamond worth owning.  Once you have this understanding, you will know what to look for.

3. The inclusions in the diamond have to be pleasing to the eye when looked at under magnification.  Even in VS clarity diamonds, and especially in SI clarities, the character and type of inclusions have a tremendous impact on the desirability of the diamond.  I don’t mean just as an investment; I mean desirable for purchase for the purpose which most buyers intend- to express love and romance to the partner of their choice.

All diamonds with the same clarity grades are not equally desirable.  An SI1 with some small white feathers on the side is a more desirable (and less expensive) diamond than a VS2 which may have a single black inclusion in the center.  When you look inside the diamond, you have to feel that the inclusions are pleasing and don’t shock your eye.

So, let’s recap what we have up to now:

1. The diamond has to have a dimension that is appropriate for its weight;

2. The diamond has to have full brilliance; and

3. The nature of the inculsions in the diamond has to be pleasing under magnification.

There is more to come in order for you to understand the type of diamond which is worth putting your money into.

Coming soon…more of what you need to know in order to buy a Pretty Diamond.

In the meantime, until next time, Mind Your Diamonds!

Josh Fishman

josh@afishman.com

www.afishman.com

What Makes a Diamond Pretty – Part 2

 

diamond-education-titlesmall

Hi again,

Let’s continue our discussion about what makes a diamond pretty.

2. The diamond has to be brilliant.

Not only must the diamond look its weight (see Part 1), it must be brilliant and scintillating.  Just because the diamond has an “excellent,” “very good,” or “ideal” (or “Signature-Ideal”) cut label, does not mean that it was cut properly.  Many diamonds whose dimensions are too small have such labels.  Some diamonds which don’t “measure up” can be very brilliant.  But these diamonds are very thick in the girdle, thereby allowing the angles of the diamond to still reflect light pretty well.  However, the diamond still looks too small and is not something which you should consider.

Coming soon, Part 3 of What Makes a Diamond Pretty.

Until then, Mind Your Diamonds!

Joshua Fishman

josh@afishman.com

www.afishman.com

What Makes a Diamond Pretty – Part 1

 

diamond-education-titlesmall

Hi again,

Are you are looking for that special diamond and want to be sure that not only does it have a good grade and certificate, but also that it is a Pretty Diamond? 

Not all certificated diamonds are pretty, including  diamonds with “ideal,” “excellent,” or “very good” cut grades.  The certificate is only the place to start from.  There is much more to understand.  Let me briefly explain, but please do not hesitate to call me if you would like to discuss this most important issue in greater depth.

What do we mean by a Pretty Diamond?

As you probably are aware, prices for diamonds of the same size and grade can vary substantially, sometimes by 20% or more.  Some of the best known on-line diamond retailers have many diamonds listed with the same grade and cut with substantially different prices.  When comparing a grade and a price it can often seem as if the lower priced “ideal” or “very good” cut diamond is a better “deal” than the higher priced diamond.  A closer examination will usually reveal that this is not the case.

When you consider purchasing a diamond you should be looking for a Pretty Diamond!  If the diamond is Pretty (as I am about to define that term for you), all the other factors of the certificate’s statistics will fall into place within the appropriate ranges.  But how can you tell if a diamond is pretty?  You can’t if all you have to rely on is the bare bones of the certificate.  You need expert guidance. 

Let me describe the the first of four major characteristics of a diamond which must be met  to consider the diamond a Pretty Diamond worthy of your investment and consideration.  (If you would like to read about these issues in greater detail, please go to Beyond the Four C’s: What you  should really know before you buy a diamond!)

1. The physical size of the diamond in millimeters has to reflect what a well cut diamond should look like.

For example, a 1.00 carat round diamond should measure approximately 6.5mm in diameter, a 1.50ct should measure around 7.5mm, a 2.00ct should measure around 8.1-8.2mm, and so on.  If you see a diamond listed on line in the 1.00ct size which only measures 6.2-6.3mm (or smaller), you should not buy it!  That diamond doesn’t look any larger than a well cut 0.80-0.90ct diamond.  This also applies to 1.50ct diamonds which measure 7.2 or 7.3mm.  These diamonds may have a good grade on paper, even a terrific cut grade and a “great price” but it is not a diamond I would ever recommend to my private customer.  The same factor applies to fancy shaped diamonds with the additional requirement that the diamond’s shape has to be right, not just its dimensions. Below is a photograph which will highlight for you what I am talking about.  A picture is worth a thousand words.

BlueCutComparison

Coming soon: More factors which make a diamond Pretty.

In the meantime, until next time — Mind Your Diamonds!

Josh Fishman

josh@afishman.com

www.afishman.com