Customers often ask us to estimate the value of their diamond while only providing a limited description, such as its shape and carat weight. Estimating a value based on these two characteristics alone is nearly impossible. It would be like calling up a car dealership and asking them how much they would pay for a sedan without providing any other details. For example: the market price of a 1.00ct Round Brilliant diamond can be anywhere from $1,100-$28,400 (2013) depending on the diamonds color, clarity, cut and other factors.
Without any other resources, the first place a member of the public will look to as a means of determining resale value is purchase price. They assume that they can expect a certain percentage of that price when selling. An issue with this method is that depending on when and where the diamond was purchased, the percentage you should expect to receive varies.
If a diamond was purchased as jewelry from a high end retail store you can expect 40-50% of what was paid. On the other hand, if the diamond was purchased as a loose stone from a wholesaler or online distributor this percentage should increase to around 50-60%. In certain cases, when the diamond was purchased at a highly competitive rate this percentage can jump up to 60-75%. Another factor which can influence resale value is the date of purchase.
Diamond prices have slowly increased over time. Most of this can be attributed to currency inflation and growth in the market size. Purchase date becomes an important factor when the diamond was bought 15 or more years ago. During this time, the value of diamonds has inflated enough to have a noticeable impact. While this rarely means you will receive more than what was paid, it should increase the percentage you can expect to receive when selling.