Typically investment grade diamonds have no treatment whatsoever. It is important for treatments to be disclosed if there are any. Laboratories can identify whether a diamond is treated. Unless of special consideration, from an investment and resale perspective, IDIAM recommends non–treated diamonds.
In the interest of consumer, we usually mandate all suppliers to provide a return policy for all diamonds purchased on IDIAM. So until a customer is not satisfied, they can return the diamond for a full refund (minus transit and transfer charges)
When a customer purchases a diamond, their payment is not released to the vendor until the return period is over. The payment is in the custody of IDIAM and only until the return period is over, that the transaction gets completed (i.e payment is released to the seller).