Gemstone Assistant
Hover over a gemstone characteristic to learn more
Choose a Gemstone
You can choose a gemstone first or start by choosing setting.
- Choose a gemstone
- Choose a matching setting
- Review your results in "My Design" before checkout
Choose a Setting
You can choose a setting first or start by choosing gemstone.
- Choose a setting
- Choose a matching gemstone
- Review your results in "My Design" before checkout
My Design
Review your gemstone and setting selections before proceeding to our convenient checkout.
Shape
Gemstones are available in a variety of shapes, which emphasize its specific features. The most popular gemstone shapes are the Round, Princess, Emerald, Asscher, Oval, Radiant, Pear, Heart, Marquise, and Cushion Cut.
Type
Gemstones come in many types. The most popular gemstone types are Sapphire, Emerald, and Ruby
Cut
The cut of a gemstone influences how effectively it reflects light. Well-cut gemstones appear fiery and brilliant and allow light to enter the stone and be reflected around the facets before exiting the stone through the top. Poorly-cut gemstone can appear lifeless and dark, despite their clarity or color grade.
Carat Weight
The carat is the unit used to measure a diamond or gemstone’s weight. A single carat weighs 200 milligrams. In general, the larger the gemstone, the higher its value - although other factors play in value.
Clarity
Clarity refers to the presence of imperfections, flaws and blemishes inside or on the surface of a gemstone. The GIA grades gemstone clarity under 10X magnification on a scale that ranges from Flawless (FL) to I2-3 (Included)—gemstones with the least amount of flaws having the highest clarity grading. A gemstone’s clarity has a significant impact on its value.
Polish
Polish refers to the smoothness of a gemstone facets. Polish can affect a gemstone brilliance. The GIA grades polish as follows: Excellent, Very Good, Good, Fair or Poor.
Symmetry
A gemstone symmetry refers to how well the facets of gemstone are aligned and arranged around the stone. The more symmetrical the gemstone, the more fire and brilliance it will display. Symmetry is more important in gemstones that have very high clarity grades.
Laboratory
All of our gemstones are graded by the 3 most reputable gemstone grading laboratories in the world: GIA, AGS & IGI.
Learn More
Price
Select a price range that fits your budget.
Depth
Depth refers to the height of the gemstone, as measured from the top-table facet to bottom-culet facet. A gemstone depth plays a key role in giving brilliance to the stone. If a gemstone is cut too shallow or too deep, light will be lost, resulting in diminished brilliance.
Table
The table is the gemstone largest facet, situated at the top. The table is the main entry and exit point for light. Table width is quoted as a percentage.
Fluorescence
A gemstone fluorescence is its tendency to glow, usually blue, under ultraviolet light. Some studies indicate that a strong blue fluorescence is associated with a milky or hazy appearance in regular light, although the GIA has indicated that gemstone fluorescence is usually imperceptible to the average consumer.
Girdle
The girdle is the outer edge of a gemstone—the thin unpolished band around the widest part of a gemstone. The girdle protects the edge of the stone from chipping.
Culet
The culet is the face on the bottom of a gemstone that looks like a point. The culet is often polished to be flat during the manufacturing process.
Measurements
Since no two gemstones are identical in proportion, a gemstones’s measurements are primarily used for identification purposes. A gemstones’s measurements, such as its length-to-width ratio, determine its overall beauty and brilliance.
Certificate
A gemstone certificate, or grading report, is a blueprint and evaluation of a loose gemstone. A certificate will report the measurements, carat weight, clarity, cut, and other key characteristics of the gemstone. A gemstone certificate from a reputable agency assures the quality of the gemstone.
Fluorescence
Emission of visible light by a material when it is exposed to ultra violet radiation. Learn more.
Find your ring size
Having trouble determining the correct size for your engagement ring or wedding band? Here are some tips. Learn more
Contact a Representative for more information
Our knowledgeable Customer Service Representatives are available by phone and chat to assist you with any questions or concerns you may have.
They are available 24 hours a day, 7 days a week.
Please feel free to
email us any time and a representative will get back to you promptly.
Real Gemstone Photos
James Allen uses unprecedented technology to photograph each gemstone that we sell. By providing actual photos of our inventory, you can examine each gemstone exactly as a jeweler can. We are the first site to offer this important feature, and the only site to offer such a large number of real photos. Plus, with our Virtual Loupe, you can see any of our gemstones at 30X magnification. We understand the significance of purchasing a gemstone, and we guarantee you will find what you are looking for. At James Allen, what you see is what you get.
Metal
Select the type of metal you prefer. Learn More
Gemstone Quality
Many factors contribute to the overall quality of a gemstone, including cut, carat, color and clarity. Learn More
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Pavilion Angle
The pavilion angle is the angle of the pavilion facets relative to the girdle plane. Pavilion angle is a very important component of a gemstone’s proportions, because it greatly affects the amount of brilliance a gemstone will display.
Crown Angle
The crown is the top part of the gemstone, from the girdle to the table. The crown angle in a well-cut gemstone should be 33 to 35 degrees.
Enhancement
Some gemstones are grown naturally within the Earth, and others are grown in a laboratory. While they are physically and chemically identical, it’s important to distinguish their origin.
Pavilion %
Pavilion % refers to the distance from the top-table facet to the diameter of the gemstone. The percentage is calculated as follows: Distance from top-table facet to diameter/diameter.
L/W Ratio
The L/W Ratio of a gemstone compares its Length to Width, resulting in a ratio that can be helpful when purchasing a fancy shape gemstone. A ratio of 1.0 indicates a gemstone that is perfectly square or round. As the ratio increases, the gemstone becomes more elongated in shape.
