About: ABOUT gold plating, rhodium plating, ruthenium plating, anti-tarnish coating, and textures.

DIAMONDS



Diamond grading like that of other stones is based on 4 main criteria also known as the 4 C's : Color (from D to K for white diamonds), Clarity (Purity), Cut (mainly proportions and symetry), and Carat (weight).

Just like any other luxury goods, the value of a diamond depends on:

- Beauty:
Diamond has a high luster and a high diffraction index that separates the components of the white light into the colors of the rainbows, rendering the beautiful multicolor sparkling effect of the diamond in full sunlight. If tyhe diamond is clean and well cut the brilliancy will be magnificent.

- Durability:
Diamond is well known for its hardness and resistance to abrasive materials. it is this resistance that allows diamonds to resist to the erosion, to survive transportation in river beds through ages and time and finally gave the saying "Diamonds are eternal ". This hardness is due to its composition of pure carbon. Because carbon is one of the smallest elements that can be combined into a 3 dimensional matrix, in which the atoms are very close to each other, this makes a very strong bounding between them and the hardest compound.
This hardness to abrasion is not to be understood as a resistance to shocks, because diamond is cleavable, meaning that it can break pretty easily in specific directions and this property is used as a part of the diamond cutting process.

- Rarity:
Diamond value will fluctuate with its rarity and the classification by color is one of the best example. Nitrogen (70% of our atmosphere) is responsible for the yellowish color of lower grade diamonds. A white diamond was not in contact with nitrogen during its crystallization and this is rare.
On the market there are other factors (other than the 4 C's) that will influence the diamond value especially of larger single stones.




Tools:

PRICING OF SINGLE DIAMONDS, CENTER STONES

Certificates:
Laboratories will deliver certificates mostly for stones over 0.1 carat (4.5 mm).
Since the certificate cost around 120 USD we recommend to buy stones with certificate only for a weight of 0.5 carat (5 mm). Below this size our graduate gemologists will identify, select and grade the diamonds according to customer requirements.
Cost for GIA Certificate: 120 USD
Check your certificate and diamond characteristics online.

Rappaport Price guide:
This international standard will set the rate every month for rounds and other shapes of diamonds.
For each size range the table is giving a price on a 2 dimension table the Clarity (Flawless, VVS1, VVS2, VS1, VS2, SI1, SI2, SI3) on horizontal scale, and the Colors (D, E, F, G, H, I, J, K) on the vertical scale.

But as explained earlier other factors will influence this main price.
Purchase the last Rappaport price list online.

Fluorescence:
Trace elements inside the matrix can prorogue fluorescence under UV light. Since ultra-violet radiation are part of the sunlight such stones will show fluorescence outdoor and this feature is not desirable because it is rendering the stone slightly milky even if the stone is 100% clean crystal transparent material under microscope.
Fluorescence is a diffuse glowing effect (usually green, blue or orange under pure UV light in the dark also commonly called "black light") that will render the edges less visible (hide the faceting details) and can even, when it is strong, disturb the brilliancy by interfering with the rays that are supposed to bounce at the bottom of the stone and come back straight up.
Stones with Medium or Strong Fluorescence will have more discount.
We generally propose only stones with fluorescence None or Faint.

The demand and availability:
Some color/clarity ranges are offering a better quality/price/budget ratio and are more demanded therefore more difficult to find or wholesalers will give less discount on these to lessen the price gap at their advantage.

Overweight stones:
A diamond cutter is always trying to use the most of his rough by fitting the cut stone in the best part of the Rappaport price table (the entry weight of each weight range). If he cannot get a 2 carat stone he will prefer making a 1.5 carat stone and a 0.4 carat stone rather than 2 stones of about 0.9 carat each. Therefore stones that are 1.3 carat will be considered overweight meaning that the cutter did not get much value for the rough size and will sell with les discount or even raise the price over the Rappaport price.

Fancy cut:
Usually the rounds are the most expensive, the other standard shapes like pear, ovals, squares. Nevertheless a "half-moon shape" or a lozenge are considered fancy cuts and sold more expensive than standards shapes.


PRICING OF SMALL DIAMONDS FOR SIDE STONES OR PAVE
Sizes/Qualities:
We mostly use G/VS White Diamonds or G-H/SI1 quality as standards in our quotes.
Other qualities should be asked for as specific requirements.
From 0.6 mm to 0.9 mm we propose only VS or VVS quality.

Pricing:
The most important concept about small stones (diamonds and colored stones) is the selection and sorting for sizes and quality to fit jewelry requirement. This task is creating labor costs and rejections and it represents a liability as well. Therefore small diamonds selected and sorted cannot be compared in prices with wholesale prices for lots of average sizes and qualities. The difference with mix lot price would be around 15% to 20% after sorting.

Consignment:
The task and the liability are the same whether the stones are supplied by the customer or by a supplier. Therefore we apply the same charges of 15% to 20% on small goods provided by customers. Larger and costly stones will have the consignment fee down to 10% or 5% depending on the value. We base the value on our own estimates for similar goods if we were to provide them ourselves.
The gain for the customer is still important when providing his own stones because the margin of the workshop will apply only on the consignment fee (5% - 20% for stones value) instead of applying on the total stones value.

Reminder:
Our quotations are based on real labor and material costs, then we apply a margin of:
- Gold Jewelry : +20% based on our costs (which is 15% profit based on selling price to customer).
- Silver Jewelry : +33% based on our costs (which is 25% profit based on selling price to customer).
When buying large quantities the customer can get up to -10% discount

Available treated colors are as follows:
- Black Diamonds
- Champaign Diamonds
- Brown Diamonds (TTLB)
- Cognac Diamonds

- Green Diamonds
- Blue Diamond
- Yellow Diamonds
- Purplish Pink Diamonds


Treated Colored Diamonds for pave setting

Useful Links about Jewelry and Gemology

Laboratories & schools
www.aigslaboratory.com
(A.I.G.S. Laboratory)
www.gia.edu
GIA)
www.gemresearch.ch
(GRS)
www.igiworldwide.com
(IGI)
www.ssef.ch
(SSEF)
www.gubelinlab.com
(Gubelin)
www.gemnantes.fr
(D.U.G. France)
Knowledge
www.fieldgemology.org/
Field trips in the mines
http://webmineral.com
About minerals
www.ruby-sapphire.com
The best seller
www.mindat.org
Mineral database
www.themelis.com
Another famous gemologist
http://gemme.la.rca.fr
Blog gemmology and opals
www.opalinda.com
Blog gemmology and opals
Forums & Networks
www.gemologyonline.com
The rendez-vous gemology
www.geminterest.com
French equivalent
www.pricescope.com
All about prices
www.diamondse.info
Mostly about prices
http://polygon.net/
All about everything
www.ganoksin.com
All about everything
Associations
www.thaigemjewelry.or.th
(TGJTA)
www.crg-dug.frm
Gemology Research center
www.gemstone.org
(ICA)
www.agta.org
(AGTA)
www.gemsociety.org
(IGS)