A Shopper's Guide to
Diamond and Sapphire Engagement Rings

The ring features a halo setting, with a central 18-carat oval sapphire surrounded by 14 small diamonds, and the contrast between the brilliant blue of the sapphire and the white light of the diamonds makes it unforgettable.

Couples shopping for unique engagement rings may find the diamond and sapphire combination irresistible. The following information and tips will help you know what to look for while shopping for your own ring.

Jewelers evaluate diamonds, the hardest of all gemstones, by judging four characteristics: color, cut, clarity, and carat. Together these are known as the four C's of diamonds.

Color is graded on a scale from perfectly colorless to those with a yellow tinge. The cut of a diamond refers to the proportions and symmetry of each face as well as the entire stone. Round cuts are the most popular, but princess, oval, and marquise cuts are also frequently used.

Clarity rates the diamond in regards to internal inclusions, or imperfections, and external blemishes.

A carat is the unit of weight used to value diamonds. One carat equals 200 milligrams and is abbreviated as ct. The value of a single piece of jewelry is expressed as total carat weight, abbreviated as ct.tw, a combination of all the diamonds in the piece.

The carat of a diamond does not relate directly to its value. Larger carat stones are rarer, so a 1-carat diamond has a higher value than two half-carat diamonds together.

Sapphires add that extra punch to diamond and sapphire engagement rings. Sapphires are associated with loyalty and commitment, and they are also the September birthstone.

While most commonly thought of as blue, sapphires also can be yellow, pink, purple, orange, green, or black, the most unusual color. The most valuable sapphires have a medium blue color in a concentrated hue that remains constant in all types of light.

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Jewelers use the same criteria to judge a sapphire as they do to judge a diamond, with the difference that color is evaluated by slightly altered criteria.

Your choice of metal may be influenced by your choice of gemstones. Yellow gold is a traditional metal for engagement rings.

The amount of gold in a piece of jewelry is measured in karats, with pure gold equal to 24 karats. However, gold is too soft for practical use, so it is usually combined with other metals to create an alloy that is stronger and more durable. Thus, 18 karats means the ring is 75-percent gold and 14 karats is 58.3-percent gold.

White gold, platinum, and palladium are also metals appropriate for use in unusual engagement rings. Their white color enhances the contrast between the two gems in diamond and sapphire engagement rings, whereas some people feel that yellow gold detracts.

White gold is actually yellow gold that is combined with a white metal such as palladium or nickel. Platinum is 35 times more rare than gold, which makes it an expensive option. Palladium is among the newest trends in jewelry; it offers the look of platinum at the price of gold.