Options are a good thing. Except when you have so many that you don't know where to begin. Well this handy how-to-buy-a-diamond-engagement-ring guide should help.

Start here.

Cut

The cut is and is considered the most important factor when purchasing a stone. It is what gives diamonds that other-worldly sparkle while hiding blemishes and determining the shape, size and facets of the stone.

When done correctly, diamond cutters pay close attention to proportion and symmetry to allowing for maximum:

Brightness: the light reflected from the diamond

Fire: how the light is scattered through the diamond to create a rainbow of light

Scintillation: the amount of sparkles that cross the surface of a diamond as it moves under light

How cut is graded:
Ideal > Near Ideal > Excellent > Very Good > Good > Fair > Poor

Color

Diamonds come in a broad range of colors. Traditionally, white diamonds are used in engagement rings. The top of the scale, boasts "near colorless" or the whitest, and most expensive of diamonds, moving down the scale, you begin to see hints of yellow or brown.

How color is graded:
Color is graded on a 23-grade scale ranging from D (near colorless) to Z (more yellow/brown)

Clarity

The clarity grade is a reminder that, after all, a diamond is a thing of nature — and like most natural things, it's rarely perfect. Most diamonds have flaws, known as inclusions or blemishes. A good cut will hide the blemishes or work around them. The clarity grade measures these blemishes.

How color is graded:

Carat

Carat is a measurement of weight. Carat is the biggest factor in the price of the diamond and even small differences can often result in a disproportionate spread in cost.

How carat is graded:
Diamonds are graded by carat (ct) and points - with 100 points equalling one carat.

THE CURVES: What's your shape?

Like people, diamonds come in different shapes - and factor in to the ring's overall style.
What you choose is based on personal preference. Most common shapes are:

Ring Settings

Solitaire:
An elegant, beloved classic, the solitaire features a single stone with a plain mounting. Solitaires are one of the most popular engagement ring settings.

Halo: Halo engagement ring settings feature a center diamond surrounded by smaller diamonds. The smaller diamonds makes the center stone appear larger and adds to the ring's overall sparkle.

Three Stone:
Three stone engagement rings consist of a center diamond flanked by two smaller side diamonds, accentuating the size and brilliance of the center stone.

Pave:
A pave engagement ring is encrusted with very small diamonds along the band to give the appearance of a solid diamond surface. The result is such that the diamonds appear to blend together for extraordinary fire and brilliance.

Diamond Band:
Diamond band engagement rings have dazzling diamonds set through either half or all the way around the ring band.