Even without the markup, diamonds are not going to be easy to sell. A valuation based on cut, caret, color and clarity is going to be hard to do. The buyer must

Even without the markup, diamonds are not going to be easy to sell. A valuation based on cut, caret, color and clarity is going to be hard to do. The buyer must accept a risk that they have undervalued (and you will shop around to find the buyer who undervalues it the most), so they need to give themselves some margin of error.