A typical consumer will spend over $5,000 on a diamond for an engagement ring, and have no idea whether they made the right choice. More often than not, they are at the mercy of the salesperson, relying on the seller's opinion of what's best. However, choosing the right diamond is not as difficult as it may at first appear, if you follow the six simple steps below.

Things You Will Need

A working knowledge of basic diamond terminology.

Step 1

If needed, use the 4 C's of diamonds (Cut, Color, Clarity, Carat Weight) as a guide when following these steps.

Choose your shape:

Most diamonds sold for use as the center stone in fine jewelry fall into one of ten shapes: Round, Princess, Radiant, Emerald, Asscher, Cushion, Oval, Marquise, Pear, and Heart. The recipient of your diamond probably has a shape preference; you just need to find out what it is. Take note of jewelry she already owns, ask her friends or relatives, or just pay attention to what catches her eye. If you have no idea what to choose, and no way of determining her preference, choose Round or Princess, classic shapes that will not go out of style. Also, make sure the jeweler you purchase from has a clear return policy that allows you to change your mind, just in case.

Step 2

Determine your minimum carat weight:

Just as in step 1, the desires of the recipient are important here. If your partner has her heart set on a 1 carat diamond, no half carat diamond will do (no matter how flawless). The most popular carat size for engagement diamonds is between one and two carats. If your budget dictates a choice under three-quarter carats, consider the Marquise shape, which appears larger due to its elongated cut.

Step 3

Determine your clarity minimum:

Clarity is a measure of the level of imperfections present in a diamond. Virtually all diamonds contain some flaws, and are given a clarity grade from FL (flawless) down to I (included).

Begin by reducing your target clarity to as low as VS2 (the lowest clarity grade which is always "eye clean" - any imperfections are invisible to the naked eye and can only be seen with the aid of a magnifier).

If after reducing your clarity target, a diamond of your preferred shape and carat weight is within your budget, buy it. If the diamonds are still too expensive, continue to the following step.

Step 4

Determine your color minimum:

White diamonds (meaning all white and near white diamonds, including those slightly yellow in color) are usually assigned a color grade from D (absolutely colorless) to Z (light yellow). Rarely will you find diamonds in a jewelry store with a color grade under M, as the amount of yellow tint present makes them undesirable.

Begin by reducing your target color to as low as H (the lowest color grade which does not betray any color to the naked eye in normal viewing conditions).

If after reducing your color target, a diamond of your preferred shape, carat weight, and color is within your budget, buy it. If the diamonds are still too expensive, continue to the following step.

Step 5

Determine your cut minimum:

Cut refers to a diamond's symmetry, proportions, and polish. Cut is not as well understood as the other "4 C's of diamonds", but it has the most significant affect on a diamond's appearance, and for that reason is the last one to be reduced.

The Cut grade is usually expressed on a simple scale ranging from Excellent to Poor. The higher the grade, the more sparkle and fire a diamond will possess.

Reduce you desired Cut grade to as low as Very Good (the lowest cut grade that still represents above average appearance for a diamond).

If after reducing your Cut target, a diamond of your preferred shape, carat weight, color and clarity is within your budget, buy it. If not, continue to the final step.

Step 6

Final Adjustments:

1. Lower the Carat Weight target. You can shave as much as 10% of your minimum desired carat weight without a significant effect on the perceived size of the diamond.

2. Lower the Clarity target, as low as SI1. Flaws will still be very difficult to see with the naked eye, usually only perceptible if pointed out by an expert.

3. Lower the Color target, as low as J. Any color present will be perceived as a warm glow vs. a yellow cast. Because diamonds of this color grade are more common, the price is greatly reduced.

4. Lower the Cut to as low as Good. Go no lower, regardless of your needs. Diamonds that cannot achieve a cut grade of good will not satisfy in their overall appearance.

Try walking through these purchase steps to get comfortable with the process. Lumera Diamonds sells GIA certified diamonds, and presents all the information you need to walk through the selection online.

After walking through all the steps above, if there are still no diamonds available in your price range, your carat weight target is probably not realistic. Consider a smaller stone, or a larger budget.

Tips & Warnings

Purchase only GIA certified diamonds. By doing so, you will not have to rely on the seller's estimation of the various ratings discussed above. This will also filter out all diamonds which have been artificially enhanced or treated, as GIA will not certify them.

Do not purchase from a seller who doesn't offer at least 14 days for you to change your mind (for any reason) and return your purchase. This gives you time to have your diamond independently appraised if you are concerned about your choice.

Ask the seller about their trade in policy, and ignore anything they do not have in writing. If the seller is not willing to give you what you originally paid for the diamond when you trade up, you can be sure you are over paying.