Pricing Color: The Methodology & Challenges Richard B. Drucker, GG (GIA), Honorary FGA

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Pricing Color: The Methodology & Challenges Richard B. Drucker, GG (GIA), Honorary FGA Thank you for attending the Scandinavian Gem Symposium presentation on 17 June, 2017.

Although some of the pricing charts and information are included in our GemGuide with a subscription, other information in this posting are not in the GemGuide.

1 Pricing Color: The Methodology & Challenges Richard B. Drucker, GG (GIA), Honorary FGA Thank you for attending the Scandinavian Gem Symposium presentation on 17 June, This synopsis includes information presented during the talk along with more notes, including our grading system for colored gems in more detail along with pricing charts. Although some of the pricing charts and information are included in our GemGuide with a subscription, other information in this posting are not in the GemGuide. You may also me at rdrucker@gemguide.com with other questions. Treated Gemstones Identifying and valuing treated gemstones is far more challenging today. What follows is a list of major treatments and pricing guidelines. Corundum Heat & Flux Heat is the standard by which prices are based in the GemGuide. However, when flux residue is present a discount may apply per the chart below. Flux is a result of the high heat treatment process that was being done to Mong Hsu Burma rubies, starting in the early 1990s. Today these are less prevalent. The levels of flux found on a GIA report are minor, moderate, and significant. Price guidelines below.

2 Diffusion Diffusion treatment of corundum can be done by a few methods. The early surface diffusion treatment is easy to detect with immersion. Titanium diffused corundum yields sapphires and chromium diffusion results in red sapphire. Note that we do not call it diffused ruby since the starting material was not light ruby. Star corundum can also be obtained with the diffusion process. Beryllium treated sapphires are mostly undetectable without advanced testing from a laboratory. The treatment can result in a variety of colors. Charts for pricing diffusion follow. Titanium Diffused Blue Sapphire Commercial Good Fine Extra Fine 1ct. 3ct N.A. N.A. Beryllium Diffused Sapphire Pricing Commercial Good Fine Extra Fine Be-Diffused Yellow Sapphire 1 ct. 3 cts. 5 cts Be-Diffused Orange Sapphire 1 ct. 3 cts. 5 cts Be-Diffused Red Sapphire 1 ct. 3 cts. 5 cts ,850 The price difference for different colors of beryllium diffusion are due to the different starting materials before treatment.

3 Glass Composite Ruby Glass composite ruby is not a treatment of ruby. It is considered a manufactured stone. Some in the trade would like to consider this a treatment and much of this is being sold today in stores only as ruby with no disclosure or simply as treated ruby. Although prices shown here can be somewhat high for better material, it is still very low when compared to prices of heated only ruby. Also, note that much can be found in the market today for just a few dollars per carat. Emerald Treatments Using the GIA as a reference (other labs may have similar approaches or their own criteria), emeralds submitted for a report will get this statement when treated: Evidence of clarity enhancement. The scale then used is minor, moderate, or significant and this is truly an opinion as some treaters claim that this is difficult to determine and that labs often get it wrong. Many treatments are available including cedarwood oil, Canada balsam, Excel, polymers, resins, and many others. Some labs will identify the fillers, others do not, and there might be additional fees. The AGL laboratory classifies the filler as either traditional or modern. With the many fillers and the combinations of fillers, some with hardeners, it is extremely difficult to know for sure unless the trusted source discloses the treatment. The trade seems to prefer cedarwood oil as being traditional and use the term natural but this is somewhat of a misnomer since no oil is natural. They are all manufactured and nature does not enhance with any product. However, one explanation for dealers preferring cedarwood is that it is easier to clean out and retreat. Also, be aware that some unscrupulous dealers have been known to remove oils to get a report of no enhancement or minor only to then re-oil the stone and use the no enhancement report to get a premium. A valuer therefore, can only value what they see in front of them and so the emerald should be valued based on its color, clarity, and cut like other gems. When there is additional information available, the treatment effect can be used for adjusting value. With emeralds, it is not an easy task since one that might have received a discount will not if information is not known. The chart below is for treatment levels when known.

Reconciling Emerald Treatments Other Colored Gemstones Tourmaline: Possibly heat or irradiation, often undetectable especially red, usually not a price consideration.

4 Reconciling Emerald Treatments Other Colored Gemstones Tourmaline: Possibly heat or irradiation, often undetectable especially red, usually not a price consideration. Spinel: Possibly heat, often undetectable, usually not a price consideration. Garnet: Possibly heat or oil, often undetectable, some demantoid low heat, usually not a price consideration. The bottom line on all gems is that something may have been done, pricing is often not affected because it is not detected, may not be detected, or it is not disclosed. Origin and Nomenclature Gemworld s position on origin is that it is the quality that should dictate the value. Lab reports on origin are only opinions and not an exact science. Dealers have been known to submit gems to more than one lab and if reports differ, they will use the report with the best origin. However, the GemGuide must report the market, not make the market and the valuer must research the value based on the origin stated but should also attempt to research the validity of the report. The charts that follow are in the GemGuide and show the differences in value based on origin for rubies and sapphires. They also include the separate factor which is unenhanced.

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Grading Color The GemGuide system ranks colored gems on a scale from 1-10.

Grade the color with a grading system (World of Color is by Gemworld) or by experience.

Grading Clarity Gemworld uses the American Gemological Laboratories clarity grading system.

They are inclusions, texture (transparency), and the degree of unintentional zoning.

deducted for. The clarity grades are summarized here.

7 Grading Color The GemGuide system ranks colored gems on a scale from Quality categories are also shown corresponding to the grades from Lower Commercial to Upper Extra Fine. Grade the color with a grading system (World of Color is by Gemworld) or by experience. For example, the gem shown here might have been graded as 8 in the upper fine category. Grading Clarity Gemworld uses the American Gemological Laboratories clarity grading system. This system looks at three components to assign clarity. They are inclusions, texture (transparency), and the degree of unintentional zoning. Note that a multicolor stone such as ametrine or bicolor tourmaline would be intentional zoning and not deducted for. The clarity grades are summarized here. Inclusions Texture Color Zoning FI Free of Inclusions Transparent Z1 LI Lightly Included Faint Z2 MI Moderately Included Moderate Z3 HI Highly Included Strong EI Excessively Included Prominent Texture-Transparent Texture-Moderate Texture-Strong Texture-Prominent Clarity Deductions: Texture Deductions:

FI (Free of Inclusions) Deduct 0 Transparent Deduct 0 LI (Lightly Included) Deduct ½ Faint Deduct 0 MI (Moderately Included) Deduct 1 Moderate Deduct ½ HI (Highly Included) Deduct 1 ½ Strong Deduct 1

If zoning is prominent (Z3), deduct 1. Grading Cut There are many factors in assessing a cut grade. Grading a colored gem for cut is not as stringent as it is for diamonds.

8 FI (Free of Inclusions) Deduct 0 Transparent Deduct 0 LI (Lightly Included) Deduct ½ Faint Deduct 0 MI (Moderately Included) Deduct 1 Moderate Deduct ½ HI (Highly Included) Deduct 1 ½ Strong Deduct 1 EI (Excessively Included) Deduct 2 Prominent Deduct 1 ½ Zoning Deductions: For none or slight zoning (Z1) no deductions is necessary. If zoning is somewhat visible (Z2) deduct ½. If zoning is prominent (Z3), deduct 1. Grading Cut There are many factors in assessing a cut grade. Grading a colored gem for cut is not as stringent as it is for diamonds. We break down cut into three areas; light performance, proportions, and finish. For this presentation, the cut grading is simplified. Light Performance Light performance considers brilliance, windowing, and extinction. For simplicity here, only brilliance is being considered. Estimate the brilliance of the gem. Two examples are shown here. Brilliance 70% Brilliance 30% Light Performance Deductions: Judge only the brilliance by an estimate of percentage of brilliance. Do not judge the windowing or extinction for purposes of the deductions. If the brilliance is: 75% to 100% Deduct 0 60% to 70% Deduct ½ 40% to 55% Deduct 1 5% to 35% Deduct 1 ½

9 Proportions Proportions will be an analysis of the crown height, pavilion depth, bulge, girdle, table size, and symmetry. These will not be judged by any set numerical proportions but rather by eye. We are generally looking for what are acceptable proportions or those that deviate from this. Again, to simplify here, we will consider an overall assessment rather than judging every component above. Using your best judgement, deduct from 0 to 1 ½ maximum deduction. Finish Deductions: The finish will assess the overall polish of the gemstone and facet symmetry. There will only be deductions if the polish is fair or poor. Good or better polish is acceptable. Deduct as follows. Ex (0) VG (0) G (0) F (-½) P (-1) Final Grade Once all deductions have been made to the starting color grade, this final grade will be representative of the overall gemstone quality. Now, use this grade to price in the grids that appear in the GemGuide. If a range of prices appear such as $1,000-$1,200 for a final grade of 7 for example, then price it at $1,100 per carat. If a single price appears, use that price. Grading and pricing colored gemstones is a very subjective process. There is not an exact answer for any gemstone. Interpolate where needed. Use your experience to judge the final grade and adjust grade and/or price higher or lower as needed.

GIA Import File Usage (GSR)

GIA Import File Usage (GSR) Provided to GIA Clients Last Revision Date: 4 June 2009 Page 1 TABLE OF CONTENTS I. GSR IMPORT FILE FORMAT AND CONTENT... 3 II. GIA S AND DESCRIPTIONS... 5 a. Diamond Report