Now that you've decided to make the commitment it's time to buy the ring. An engagement ring is one of the most important purchases you will ever make and you need to get it right. To set your mind at ease familiarize yourself with some diamond-buying basics. Plan a budget and set some guidelines on what your are able and willing to spend. the rule of thumb is 2 months salary, but your personal circumstances may allow you to spend more or less.

Some important diamond basics: Carats are the unit of measure in which diamonds are weighed. While the size of the diamond you purchase is important, the biggest stones are not always best. You must also consider the shape, cut, and clarity of a diamond to determine it's value. Diamonds come in many shapes--pear, round, square, rectangular, marquise, oval and even heart-shaped. Cut does not refer to the shape, it refers to the number and angle of the facets cut into the stone. Facets reflect light and determine the diamonds sparkle and brilliance. A diamond that is too broad and shallow will not reflect as much light. A narrow deep diamond will have similar problems. The brilliant round cut in a yellow gold setting is the most common and one of the most attractive choices. Your significant other may prefer bolder and more daring shapes and settings so pay attention to her other jewelry and hints she may drop about her likes and dislikes.

Diamonds can also vary in color. Generally, the less color the better when it comes to the the diamond in an engagement ring, but some colored diamonds are quite rare and valuable. Watch out for stones that appear unflatteringly yellowish or cloudy. Clarity goes hand in had with color. Imperfections and flaws in the stones, although they may be imperceptible to the average person's eye, lower the value of diamonds.

After choosing a stone that meets your expectations and price range look for a setting that will make the most of the diamond. Yellow gold is the most common but white gold, platinum, and titanium are also popular. The beauty of your diamond can be accentuated with smaller gemstones. Smaller diamonds set around the center diamond can also make the ring look bigger. For example a Bezel setting completely surrounds the center gem. Consider your fianc's taste and style and choose something similar to pieces she already owns or jewelry she has admired in magazines or on friends.