Key to Understanding Descriptions Used
To understand how AMR Previewers examine jewelry and how AMR describes this process, please be aware of the following.
- Prices listed under "Final Price" are taken from auction gallery records and include the buyer's premium.
- For international auction results, the final price is expressed in US dollars (including buyer's premium at the time of sale).
- The weight of the entire piece is in pennyweights. The maximum weight of our scale is 64 dwts: if the weight is not included it is because the piece was over scale and is designated as "OS."
- Please be aware that the photos shown may or may not be actual size. For actual size, please refer to the "Size in Inches" line.
Jewelry is examined at auction galleries under "as is" conditions, using available lighting. At times, the Ott light is brought to the preview because it affords a neutral lighting environment (5000K). Jewelry may not be completely clean; stones described are observed in their mountings. Because of this difference between examining gems and jewelry under laboratory conditions and under auction conditions, AMR likens its descriptions to "Desktop Gemology."
We describe material in every day language and make comparisons to similar lab terminology. We assume that gemstone treatments (for color or clarity enhancement) have occurred as customary in gem processing procedures, unless accompanied by a gem lab report indicating otherwise.
We also describe the examination conditions. Because the auction area is not a laboratory environment, we use broad descriptive terms, as illustrated in the charts which follow.
For each item, AMR provides the following information:
- dimension
- gemstones
- gross weight
- metal type
- construction quality
- era or period
- condition
- signature, if any
Such description, combined with photos, enables you to better envision the piece you are researching.
Condition
Terms used in the Condition field are defined as follows:
- Excellent - New condition
- Very Good - Like new, requires slight polishing
- Good - Slight wear but no refurbishing required
- Fair - Some wear, requires some refurbishing
- Poor - Badly worn, requires major repair / restoration
NOTE: These definitions apply to all jewelry periods. However, the marketplace is harsher on modern pieces with excessive wear than on antique or period items in similar condition.
Color Communication for Diamonds
There are two sets of diamond color grading criteria:
- one for colorless to near colorless material
- one for diamonds with prominent color
For those stones which are judged for absence of color we use the following terms:
White, Off White, and Some Color (yellow or brown) VISIBLE IN THE FACE UP POSITION.
The gems which the trade generally labels as "fancy" colors are described using the GemDialogue color saturation scales for physical comparison. Those of you who have the GemDialogue System will be able to visualize, the actual saturation level of the stone. For further information about GemDialogue, contact Howard Rubin at Auction Market Resource.
The following chart compares AMR's Desktop Gemology terms with those generally used in the trade labs:
| AMR Color Terms | Lab Comparison | AMR Description | Lab Description |
|---|---|---|---|
| White (Colorless) | D, E, F | Appears colorless to the naked eye | Appears colorless when matched against master set |
| Off White (Nearly Colorless) | G, H, I | Nearly colorless to naked eye. Very slight tints of yellow or brown visible | Slight color when matched against master stones |
| Some Color (Yellowish or Brownish) |
J to Z | Slight color tints easily seen by eye in the face up position. | Color tints match master stones with same colors. |
| Prominent Color | Fancy light, fancy or fancy intense, fancy dark, fancy deep, fancy vivid. | Prominent colors in the face up position are matched against the colors of the GemDialogue color charts. These are used as a master color set. Over 60,000 colors can be seen and matched against. | Color terms vary with examiner. No comprehensive master set has as yet been accepted on an industry wide basis. |
Colored Stone Description
Color, in gemstones and diamonds, is described using the GemDialogue color saturation scales. Each chart shows 10 different saturation levels from strong to weak. If a stone has good color but faces up somewhat dark (due to blackish or brownish tones) then gray or brown scales will be added to the description. These are called masks and serve to simulate such face up appearance. All charts in the system are transparent and may be combined when necessary.
The GemDialogue verbal description breaks down the color into two primary parts:
- color
- saturation level (i.e., moderate purplish blue with light, moderate, or strong saturation)
A third segment precedes this description if a color mask is used (i.e., slightly, moderately dark, or very dark, moderate purplish blue with light, moderate or strong saturation).
Clarity
Due to the limiting conditions of examination by AMR preview associates at the auction galleries, AMR does not apply the GIA standard grading system for clarity grading. AMR evaluators judge how visible the inclusions are to the eye AND how visible they are with a loupe (10X power) on the following scale:
| AMR Description | Approximate Lab Description | By Eye | With Loupe |
|---|---|---|---|
| VVS (Internally flawless will only be used if accompanied by a lab report) | Internally flawless, VVS1-2 | Not visible by eye | Absent, or very difficult to see with a loupe |
| VS | May include lab VS grade and some SI1 inclusions not seen in the center | Not eye visible | Still difficult to find with loupe |
| SI | Includes SI-1 & 2 grades | Not eye visible | Seen easily with loupe |
| I | Includes all I lab grades | Visible to easily visible to the eye | Seen easily with loupe. Prominent inclusions seen by eye and loupe. Extremely obvious inclusion will also be mentioned under "Notes." |
NOTE: These clarity terms will be used for both diamonds and colored stones. If a lab certificate accompanies the stone, the lab description will be provided, along with the previewer's notes, if not in agreement.
Cut Grade
The eye appearance of the stone is a strong indication of how well the stone is cut.
| Cut Grade | Definition |
|---|---|
| Excellent | Even color face up with no window, excellent symmetry and meeting of facets |
| Very Good | Even color face up, very good symmetry and facets meet fairly well |
| Good | May show small window, symmetry slightly off and facets do not quite align properly |
| Fair | May show larger window, culet off center, facets unevenly distributed. Windows in colored gem material will show a different saturation level than the rest of the stone. The GemDialogue colors for the window and the perimeter will be noted if markedly different. |
| Poor | May show large window, table and/or culet off center and uneven or missing facets |
NOTE: Chips and scratches are addressed under "Notes."
Polish Description
Describes the surface characteristics of a gemstone
| Excellent | No scratches, abraded facets, or polishing marks present. |
| Very Good | No scratches, but some polishing marks and/or very slightly abraded facets present. Seen with difficulty by eye. |
| Good | Slight scratches present and/or slightly abraded facets and/or polishing marks. Seen by eye but not in a prominent position. |
| Fair | Worn material, but may be repolished — more prominent scratches, abraded facets, and polishing marks. Seen easily by eye in the face up position. |
| Poor | Very worn material, needs recut — very prominent combination of scratches, abraded facets, and polishing. Seen very easily by eye, face up. Borders on damage instead of scratches and abrasions. |
Transparency
Describes the degree to which the interior of a gem may be examined in the face up position, determined by the amount of light the gem allows to pass through it.
| Transparent (TP) | Allows an unobstructed view of the interior of the stone, face up, from table to culet |
| Transparent to translucent (TP-TL) | Allows a slightly obstructed view of the interior of the stone, but the table and culet may still be seen in the face up position. |
| Translucent (TL) | Here we begin to see a more obstructed view of the stone's interior. Surface or near surface inclusions may be examined from the top, but inclusions near the culet require the stone to be examined from the back. |
| Translucent to opaque (TL-OP) | Allows some passage of light through the interior of the stone, but the view is too obstructed to allow a proper examination of the interior. |
| Opaque (OP) | No light passes through the stone and no examination of the interior is possible. |
Brilliance
AMR determines that brilliance is a combination of both transparency and cutting and that if all other factors are equal, highly saturated material will always appear less brilliant than lightly saturated material. Since we already describe the cutting, transparency and color, it is not necessary to include a brilliance description. Differences of hardness and refractive index are also factors and do not allow all material to achieve the same level of brilliance.
The above terminology to describing color, clarity and cut provides a practical approach to characterizing material that is not seen under laboratory conditions. However, our reviewers are trained gemologists/appraisers and look at the pieces with well-practiced eyes.
Pearl
Descriptive data consider factors which are a bit different than those considered for gemstones. The following table lists those factors and explains what we look for:
| meter Size | For loose round pearls one dimension is given. For off round and baroque shapes, two dimensions are given. For graduated strands, the smallest and largest measurements i.e., 4 to 8 mm. For uniform strands, there is usually .5 mm variation between the largest and smallest pearls, indicated as 6 to 6.5 mm. |
| Pearl Color | This refers to the basic predominant color you see. |
| Overtone | This refers to (a) color(s) which appear(s) to overlay the basic color (as above). |
| Luster | The degree of detail of reflections which can be seen on the surface of the pearl. A strong luster will show sharp edges of whatever is being reflected, such as a light bulb, a face, or a pencil. Lower luster will show fuzzy edges of the item and poor luster may not have a surface reflection at all. |
| Nacre | This refers to the thickness of the layers which the oyster has deposited on the mother-of-pearl seed material. The oyster considers the seed, or even sand, an irritant and deposits material over it. The thickness may be seen in the drill holes of pearls, but if the pearl is cemented to a post or a strand is knotted very tightly then it is hard to judge. In these cases, we use the luster as a guide to nacre thickness; if the luster is high we feel the nacre is thick, and if the luster is low then the nacre must be very thin. |
| Match | Pearls should be either well matched for color or properly blended. If shape or luster is badly matched it will be mentioned in "Notes." |
| Blemishes | Blemishes refer to spots, wrinkles, indentations, bumps and/or orange peel surface. Description explains how noticeable they are to the naked eye. Unusual combinations of blemishes will also be reported in "Notes." |
| Full Pearl | We report if pearls have been shaved or ground down to ½ or 3/4 pearls. |
| Shape | Shapes will be described as round, off round, pear, barrel, button semi-baroque and baroque. Some baroque shapes will be defined as a figure (Donald Duck, a bird, etc.). |
| Processed | Most pearls go through a processing procedure in which they are irradiated, bleached and/or sometimes dyed. Detection may prove difficult outside of lab conditions. |
Abbreviations Used
| Abbreviation | Meaning | Abbreviation | Meaning | |
| Bag | Baguette | OP | Opaque | |
| Bar | Baroque | OS | Over scale | |
| BO | Black Onyx | Ov | Oval | |
| Br | Brown | Pr | Pair | |
| Cal, CAL | Calibre | Prl | Pearl | |
| CC Rect, CCRE | Cut Corner Rectangle | RBC | Round Brilliant Cut | |
| CC Square, CCSQ | Cut Corner Square | RC | Rose cut | |
| CC Tri, CCTR | Cut Corner Triangle | Rd | Round | |
| Ctw | Total Carat Weight | Rect | Rectangle | |
| Cush | Cushion | Ru | Ruby | |
| CYAN | Equal Mix of Green and Blue | Sa | Sapphire | |
| Dia | Diamond | SC | Single Cut | |
| Ex | Excellent | Sim | Simulated | |
| Fac | Faceted | Sl | Slight(ly) | |
| FC | Full Cut | Str | Straight | |
| Gd | Good | Syn | Synthetic | |
| Gr | Gray | Tap | Tapered | |
| Imit | Imitation | Th | Thick | |
| MAG | Magenta | TL | Translucent | |
| Med | Medium | TP | Transparent | |
| Mod | Moderate | Tri | Triangle | |
| Mod Br | Modified Brilliant | VG | Very Good | |
| MOP | Mother of Pearl | WG | White Gold | |
| Nat | Natural | Wh | White | |
| Oct | Octagon | Yel, YLW | Yellow | |
| OE | Old European | YG | Yellow Gold | |
| OM | Old Mine |