The four C's are cut, color, clarity and carat. Each of the 4 C's effects the price of a gem stone. The most important of the C's is the cut of the stone. Our stones at ECO Diamond simulants are cut to ideal hearts and arrows standards for maximum light reflection. This brings out all fire and brilliance in a stone. Our Pure Carbon Eco Diamonds or Lab Created Diamonds vary in cut depending on the stone. The 2nd of the C's is color. This can vary greatly from stone to stone. Our ECO Diamond Simulants are D in color. This is the highest grade in color. This means that our stones are colorless. Our Pure Carbon ECO Diamonds vary in color depending on the stone. The 3rd of the C's is Clarity. Again clarity varies from stone to stone. A cloudy stone is not very desirable. Our ECO Diamond Simulants are Flawless in clarity. This is the most desirable. Our Pure Carbon ECO Diamonds vary in color depending on the stone. The last of the 4 C's is Carat. Both our ECO Diamond Simulants and ECO Diamonds come in most any carat size you desire. We stock .25 Carat stones all the way to 5 Carat in our diamond simulants. For a list of inventory on our ECO Diamonds please visit our Loose Lab Created Diamonds page.