To Whom This May Concern,
 
I just bought a pearl necklace and set of pearl earrings, but I was unable to ascertain the nacre on those pearls. Will all the specs of the pearls come with the purchase? Otherwise, can you tell me the nacre level?
 
Sincerely, Seth B.
 
Dear Seth,
 
Thank you for shopping with PurePearls.com! The Akoya pearl’s nacre thickness can really only be measured using X-rays at a gemological laboratory like GIA, which charges between $125.00-$150.00 for the service and complete gemological certification. While we can certainly send your pearls to GIA for testing, we do not regularly have all of our pearls X-rayed or certified scientifically due to not only the added expense but also the basic parameters vis-à-vis nacre thickness in Akoya saltwater pearls. The exception is our Hanadama grade Akoya pearls which are all examined by the Pearl Science Laboratory (PSL) in Tokyo, Japan and issued a gem certification that details attributes such as luminescence, nacre thickness, refraction and reflection rates, blemish rates and such. I can assure you that we purchase only the finest quality Akoya on the market and our AAA Quality are equivalent to Mikimoto’s A-1 Grade, which is quite excellent by today’s standards.
 
Typically, saltwater Akoya pearls are left to accrue nacre for a period of 8-12 months inside the oyster; this cultivation time is drastically shortened from the early days of pearliculture (1915-1940ish) when many farmers would leave their oysters in the water for a period of 2 to 2 ½ years or so, slowly depositing nacre around the bead nucleus. This is due to a variety of reasons, but the biggest reason is the most obvious- the faster turnover a farmer can have in getting his harvests to market, the more money he makes. However this shortened time frame (which has occurred gradually over a period of decades) also results in pearls with nacre deposits literally measuring in the microns. Even the very finest Akoya pearls (Hanadama Quality) have minimum nacre standards of between 0.4-0.8mm; standard Akoya are closer to about 0.3-0.4mm approximately which is true whether you are purchasing Chinese or Japanese Akoya pearls. That said, the larger the pearl is, the longer the farmer must keep it in cultivation and does accrue more nacre out of sheer necessity- so, a 9.5mm pearl will have thicker nacre than a 6.5mm pearl, etc.
 

Nacre thickness is an important factor when trying to decide which pearl types to purchase, and a quick and easy way to visually evaluate whether a pearl has enough crystalline material around the bead nucleus to last through the years is to gently roll sections of the strand between your thumb and forefingers and look for what we call “blinking”, which is best described as a light or dark flicker of the bead nucleus visible beneath the surface of the pearl. With the 6.0-6.5mm and 6.5-7.0mm pearls, you may see some blinking in our pearls, but our AAA Quality is very fine, and for the most part our pearls err on the side of 0.4mm; the larger pearls such as 8.0mm and up almost never show this kind of phenomenon.

The picture below is of a black saltwater Tahitian pearl, but the cross section clearly shows the interior bead nucleus and the measurable nacre surrounding the bead… As you can see, the nacre on the Tahitian pearl is rather thick, measuring about 3.0mm; an Akoya pearl’s skin would be much thinner than this. French Polynesia (where Tahitian pearls are cultivated) have export laws that screen out any pearl with less than 3.0mm nacre thickness in order to maintain very high quality standards for the exotic Black pearls.

 
I do hope that you enjoy the pearls that you purchased from us, and found my answer helpful to you. Please feel free to contact me anytime if you have other questions or you would like additional information regarding the famous Akoya- I am always happy to be of assistance! Thank you again for shopping with PurePearls.com, and have a wonderful day!
 
Sincerely,
 
Ashley M.

Sales VP, PurePearls.com