Jewelcutter.com - Oregon Sunstone Grading System

For a better understanding of the color tone values used in this Sunstone Grading System please read Common Sense Gemstone Grading.

Sunstone (Feldspar)
Date - Pricing as of March 2007

Oregon Sunstone Grading - by Jeff R. Graham - copyright 2007

There is no current grading system for Sunstone. So I have created what I think is a versatile common sense grading system.

Color: Red, green, yellow, watermelon, schiller, blue/green, blue, copper, orange.

Note: There are many types of Feldspar and depending on the location the material may have various colors as well as schiller (suspended color particles of copper usually). But the term Sunstone is generally reserved for the material found in Oregon, USA.

Sunstone at this point in time is still some what of a novelty gemstone. However because of it's unique properties I believe Sunstone will eventually become a world recognized gemstone.

Note 2: All Feldspar is not much over 6 to 6.5 on the Moh's hardness scale and it has 2 distinct cleavages (that are usually not a big issue during cutting). So Sunstone is basically a gemstone that works best in protected settings or in pins and pendants, as well as earrings where the stone(s) will have some protection from hard wear.

There are 3 basic types of Oregon Sunstone.
Clear yellow/champagne - This material is the most common and can often be confused with other types in the feldspar group.
Color with schiller - This is the largest category. Schiller is copper particles like grains suspended in the clear/champagne colored material. Schiller is copper colored and often does have other colors as well as the schiller copper in the same stone. The color/schiller is almost always in layers and spots surrounded by the clear/champagne material.
Color - This is material is the rarest and there can be a very tiny amount of schiller in this, but the material is basically open with little to no schiller of any type. The color is almost always in layers and spots surrounded by the clear/champagne material.

Colors and Rarity of Oregon Sunstone
Clear yellow/champagne - This material is the most common and the least expensive.
Copper/pink/orange - This material pretty common and there is usually some schiller, although material with no schiller copper/pink does occur.
Rootbeer - This color occurs at some mine locations and can be a bit milky. This color also can be caused by red/pink and green mixing to cause the color, either in the stone or poor orientation during cutting.
Bi color, Tri color - Usually watermelon red/green, but can occur in various color combinations.
Red - This color is considered one of the most valuable and is not a common color.
Green - This color occurs rarely and is a collector color.
Blue - Usually a blue/green or teal, some times a Turquoise blue, very rare and a collector color.

Dichroic and Trichroic Sunstone - The dichroic material is not common but around, it is usually pink/orange/copper to green/teal in nature. Trichroic is rare and usually involves pink/orange/copper to teal/green/blue. The effect of the dichroic or trichroic material is that the colors occur on different axis's and the color(s) appear to move around. Great care must be taken in orientation of these types to prevent mixing the colors incorrectly and creating an ugly finished color. The effect of the various colors moving and mixing is called pleochroism.

Note 3: Some of these values and rarity of colors may vary depending on the mining and what is being found.

Note 4: It is important to separate schiller material from colored material with little or no schiller. Schiller as it becomes stronger than the "Pale" or "Light" stage starts to block light because of the particles/layers of copper schiller. So basically any Sunstone that has more than a light amount of schiller is carving or cabbing material because it will not facet well.

Note 5: There is a rarity in most color Sunstone as it gets above 4 carats and clean. I generally price it in the upper range. Above 8 carats is rare, above 12 carats is a collector stone in color.

Champagne
Pale (almost colorless to 15% tone) - Pale to light yellow/champagne.
Comments - This material actually can be valuable, especially when cut into a large unusual designs.
Pricing - In general pricing this material is more about cutting labor than any thing else. I generally price this material $8/ct to $32/ct and a minimum of $150 for a small stone to cover the labor.

Schiller - This material is basically all carving, not faceting with the exception of very light schiller which can be faceted if orientated and handled correctly.
Light (15% tone to 30%) - Light with a copper/pink tint. Can be color with the schiller.
Comments - This material actually is valuable and I sell it faceted quite well, especially when cut into a large spectacular design.
Pricing - Pricing this material is still about labor. I generally price this material $18/ct to $32/ct and a minimum of $150 for a small stone to cover the labor.

Medium (45% tone to 65%) - Schiller with a medium copper/pink or other color (red, green, bi color).
Comments - This material is valuable and not always easy to acquire. This material is cabbing and carving grade, particularly the multiple colored schiller.
Pricing - Pricing this material is cost of goods and labor. I generally price this material $32/ct to $120/ct and a minimum of $150 for a small stone to cover the labor.

Medium/Dark (65% tone to 85%) - This is what I would consider to be the top color range in carving. Very intense green/copper/red color but still light enough to distinguish the carving and light patterns in the design of the finished stone.
Comments - This material is valuable and difficult to find. I cut this material in whatever size the stones require.
Pricing - Pricing this material is cost of goods and labor. I generally price this material $90/ct to $600/ct and a minimum of $150 for a small stone to cover the labor.

Bi Color - No or very little schiller.
Light (15% tone to 30%) - Light green/teal/blue with light pink/red center.
Comments - This material is valuable and I sell it faceted quite well, especially when cut into a unique design.
Pricing - I generally price this material $90/ct to $140/ct and a minimum of $150 for a small stone to cover the labor.

Medium (45% tone to 65%) - Medium green/teal/blue with red center.
Comments - This material is valuable and not always easy to acquire. I cut this material in what ever the rough will cut and typically use unique designs
Pricing - I generally price this material $120/ct to $360/ct and a minimum of $150 for a small stone to cover the labor.

Medium/Dark (65% tone to 85%) - This is what I would consider to be the top color range in Sunstone. Very intense green/teal/blue/red color but still light enough to distinguish the facet and light patterns in the design of the finished stone.
Comments - This material is valuable and difficult to find. I cut in unique designs.
Pricing - I generally price this material $240/ct to $480/ct and a minimum of $150 for a small stone to cover the labor.

Green - No or very little schiller.
Light (15% tone to 30%) - Light green/teal.
Comments - This material is valuable and I sell it faceted quite well, especially when cut into a large stone.
Pricing - I generally price this material $90/ct to $140/ct and a minimum of $150 for a small stone to cover the labor.

Medium (45% tone to 65%) - Green/teal.
Comments - This material is valuable and not easy to acquire. I cut this material in what ever the rough requires typically use unique designs
Pricing - Pricing this material is cost of goods and labor. I generally price this material $120/ct to $360/ct and a minimum of $150 for a small stone to cover the labor.

Medium/Dark (65% tone to 85%) - This is what I would consider to be the top color range in Green/teal. Very intense green color but still light enough to distinguish the facet and light patterns in the design of the finished stone.
Comments - This material is valuable and difficult to find. I cut this material in the smaller to medium size ranges (6mm to 12mm) and typically use unique designs
Pricing - Pricing this material is cost of goods and labor. I generally price this material $240/ct to $480/ct and a minimum of $150 for a small stone to cover the labor.

Red - No or very little schiller.
Light (15% tone to 30%) - Light red, some times with an copper/pink tint.
Comments - This material is valuable and I sell it faceted quite well, especially when cut into a large stone.
Pricing - I generally price this material $140/ct to $260/ct and a minimum of $150 for a small stone to cover the labor.

Medium (45% tone to 65%) - Red, some times with a slight copper/pink.
Comments - This material is valuable and not always easy to acquire. I cut this material any way I can get it.
Pricing - Pricing this material is cost of goods and labor. I generally price this material $180/ct to $400/ct and a minimum of $150 for a small stone to cover the labor.

Medium/Dark (65% tone to 85%) - This is what I would consider to be the top color range in red. Very intense
red color but still light enough to distinguish the facet and light patterns in the design of the finished stone.
Comments - This material is valuable and difficult to find. I cut this material in the smaller to medium size ranges and typically use unique designs
Pricing - I generally price this material $240/ct to $600/ct and a minimum of $150 for a small stone to cover the labor.

Special - As we all know as cutters some times a stone just comes out "special" for what ever reason. On these kinds of stones I basically price how ever I feel like. Because this stone comes under the "special" category I often do not care if I sell the stone or not. So I usually price it high enough that if I do sell it, I get a very good price. Enough to make me say "Oh well..." and sell it. So be aware that some times I just price a stone high because I do not care if I sell it. Ironically these stones usually sell the fastest...