How To Grade Gemstones

It is a common perception that people think that only diamonds have grading. However, they do not know that there is also a set of criteria to figure out the grade of the gemstones.

Following are the basics to determine the gem’s grading:

1. Color of gems

Basically, the value of the gem is based upon its color. Natural gemstone usually reflect tertiary colors(red-orange, yellow-green, or blue-violet) and zero percent saturation( Mainly, a saturation is a state where color contains 0% of gray).

2. Color Grade

A color grade  illustrates  the  composition of  main color  as compared  to other visible colors in the stone. A stone with 100% color grade consider falls in the category of  fine quality. Following is a  measurement scale:

     Excellent: 1-2

      Very Good: 3-4

      Good: 5-6

      Fair: 7-8

      Poor: 9-10

 3. Color tone

 Any color grade is seen in combination with the tone. In a rare case,  a colored stone could be white (light 5) or black (Dec 95) with just a hint of color. Basically, it reflects the lightness or darkness  of the stone.  If a stone is too light in tone, the color will not be rich enough. In a vice versa case, if a stone is too dark, then it will  be devoided with transparency and brilliancy.

 Tone Scale :

 Very Light: 0-20

 Light: 25-35

 Light-Medium: 40-50

 Medium: 55-65

 Medium-Dark: 70-85

 Very Dark: 90-100

4. Color Zoning

 There  are various  stones, which  depicts colors only in partial area or layers.  Following  is a measurement  scale  to determine  the traits  as per  the color zoning.

 None : The color is  distributed  in the equal proportion.

 Faint :  it  depicts the visible changes in color saturation.

 Gradual : Gradually  weaken of color in certain part.

 Visible :  Stone has clear color patches or layers.

5. Clarity

 It  is yet another factor that determines the value of the stone. Generally, clarity is judged with a 10x lens. Commonly, it is termed  as “Free of Inclusions” over “Lightly”, “Moderately”, “Heavily” to “Excessively Included “.  Following is a measurement scale for the clarity:

Free of Inclusions: FI

Lightly Included: LI1-LI2

Moderately Included: MI1-MI2

Highly Included: HI1-HI2

Excessively Included: E1-E2-E3

 6. Depth

 It includes the height of the stone divided by its minimum width. Ideally, it lies between the range of  60% and 80%. Mainly, the depth is decided by the given shape of the rough stone. Stones below the 50% is called shallow. It is hard to find a maintain saturation in a light tone shallow stone.

7. Cutting Grade

 It  is a numeric number that describes the proportions and geometry of a gem.  The finish grade reflects the polish of a gem.  Following is a scale:

Excellent: 1-2

Very Good: 3-4

Good: 5-6

Fair: 7-8

Poor: 9-10

Accepted  parameters

  Carat Weight:  1 carat or larger

  Color: Good (6) or better

   Tone: It is the most accepted  tone for ruby, sapphire and emerald ranges from medium to        dark (65-85).

   Clarity: Moderately Included Two (MI2) or better

   Average Brilliancy: 50% or more

  Cutting/Finish: Good (6) or better

Following is list of laboratories that offer Gemstones Grading :

  • International Gemological Institute (IGI), independent laboratory for grading and evaluation of diamonds, jewellery and colored stones.
  • Gemological Institute of America (GIA), the main provider of education services and diamond grading reports.
  • Hoge Raad voor Diamant (HRD Antwerp), The Diamond High Council, Belgium is one of Europe’s oldest laboratories.
  • American Gemological Society (AGS) is not as widely recognized nor as old as the GIA.
  • American Gem Trade Laboratory which is part of the American Gem Trade Association(AGTA), a trade organization of jewelers and dealers of colored stones.
  • American Gemological Laboratories (AGL)
  • European Gemological Laboratory (EGL)
  • Gemmological Association of All Japan (GAAJ-ZENHOKYO), Zenhokyo, Japan, active in gemological research.
  • Gemmological Institute of Thailand (GIT) is closely related to Chulalongkorn University
  • Gemmology Institute of Southern Africa, Africa’s premium gem laboratory.
  • Asian Institute of Gemmological Sciences (AIGS), the oldest gemological institute in South East Asia, involved in gemological education and gem testing.
  • Swiss Gemmological Institute (SSEF), focusing on colored gemstones and the identification of natural pearls.
  • Gubelin Gem Lab, the traditional Swiss lab.

Gem Shows – Tips To Attend A Large Gem And Mineral Show

Gem ShowAre you looking to explore the major gem show and not sure about the necessary preparation before attending any such event. Read the below mentioned blog post, it will help you for sure:

List out  the vendors that  are participating in the show

You can browse all the information through the net. In fact, you can purchase few bead or rock and mineral magazines  in order to brush up your basics. Usually, big organizations invite many vendors who display their items at different designated locations on a same date. In fact, such events are organized on an annual basis in association with same vendors. So, once you become aware about them the very next time you will go to them in much easier way.

Gem SHow 2

Location  of the show

Generally, gem shows are organized in spacious buildings or in hotels. Moreover, some shows are organized in a little shelter as well. So check out the weather feasibility  see whether or not you can manage with certain weather conditions. Other than aforementioned, sometimes you might need to struggle with parking area as well.

 Do not carry heavy items

Do not carry unwanted items to the show. Carry  a small purse containing credit cards, driving  license, business card and bank debit card in order to churn out money from the machine. You  should also carry  drinking water and refreshments.

Gem Show 3

Be wise in shopping

Keep in mind that such exhibitions are  not the ideal place for looking for the low price range items. Moreover, you can not do bargaining  in a show. These are the places where you can get a sense of ongoing trends  in the jewellery market.  Apply your discretion before making your final purchases.

Natural Gemstones – How To Choose

Precious GemstonesThere is an extensive market related to gemstones and jewellery  This industry incorporates the involvement of a large number of people with various acumen. Whereas, a few are engaged with processing functions, others are occupied with sales and marketing. Altogether, there are jobs in different verticals. The industry is worth million dollars with several negative and positive aspects. The positive aspect includes the easy availability of jewellery items that you can like. High pricing with, and various opportunities for cheating   ( especially for the laymen) could be counted as negative points.Natural Gemstones
It is a common practice to charge much higher price than the actual market value of jewellery items. It is a quite tough to assure whether or not you are paying the appropriate price range. Usually, consumers are not expert, and most of the time they rely on others in order to make sure that they are paying the right amount for the desired jewellery piece. Well, there are certain guidelines, which everybody needs to be learned in order to attain a basic knowledge on the subject:
First and foremost, gemstones are divided into four categories. In fact, the pricing of the gemstone depends upon the category in which it falls:
Natural Stones
As the name suggests, the natural form is abstained from any sort of hardcore processing. Only processing is carried out for cutting and polishing. As they are procured in the natural form, so they are available with few impurities.
Genuine Gemstones
This form is alike to natural stones, besides it contains extreme process of polishing and cutting. The form of stone is gone through chemical treatments in order to enhance the looks and durability. However, chemical treatments which can change the entire formation of the stone is not accepted. Following is a list of treatments which is accepted widely:
Heat treatment
Heat treatment is very common and accepted quite widely. The changes occur through heat treatment are quite permanent, and applies on whole stone not just on the surface.
Diffusion treatment and Facture filling
Usually, this method does not change the stone, but the surface portion. This treatment is not accepted until the price of the stone reflects the lesser value.
Synthetic Gemstones
This form of the gemstone is produced in a laboratory. It is a much cheaper option as compared to genuine and natural stones. Although, they have the same characteristics as natural stones, and it is tough to differentiate between the two.
Imitation Gemstones
These are built on simple crystal structures. Basically, it is carried out to enhance the colour  It is alike to real gemstone, but certainly not the real one. This form of gemstones can be procured from any material including glass and plastics. Although, you can find high quality stone as well made through this way, but it is a lesser quality stone as compared to natural stones.

Top 10 Rarest Gemstones

Visit our site for more. Best In Gems, Inc. features a collection of loose gemstones, precious and semi precious gemstones from around the world since March 1999. Our goal is not only to provide gemstones for sale, but also educate and update the buyer about the quality and characteristics of the gemstones. Buying from Best In Gems, Inc. is just not a transaction of gemstones; it is a commitment. Commitment of RELIABILITY, commitment of SERVICE and commitment of DEPENDABILITY.