You can never go wrong getting a woman a diamond. After all, they are a girl's best friend.

But, before you go all out and get a diamond for your favorite lady, you might want to find out a few things about her.

Every single diamond is different. You may have heard about the 4 C's of diamonds: cut, clarity, color, carat. Yes, these qualities are important, but there's more to finding the perfect diamond. The size and shape of the diamond are going to be important, too.

There is a shape for every woman, and most women already have their favorite diamond shape in mind. Round, princess, emerald, asscher, marquis, oval, radiant, pear, heart and cushion are the different sizes that diamonds come in. Make sure you find out which one she likes.

The carat (one of the C's) is the size of the diamond. Believe it or not, there are plenty of women who would rather have a smaller, daintier diamond, rather than a large, bulky diamond. There are women who complain that bigger diamonds get caught in their hair and on their clothes (although usually, it's the setting that gets caught), so make sure you know the size diamond she wants.

Of course, there is also the question: Silver or Gold? There is a myth that women want gold. On the contrary, there are plenty of women who prefer white gold and silver to accompany their diamonds. So, be sure to find out.

It's not a bad idea to go window shopping to figure out what she wants or consult with a custom jewelry like Brian, who can listen to her every whim and create her dream diamond ring.