Is the transaction that involves buying jewelry from a person in need, then selling it back to them at a higher price after they request to keep it and pay a down payment, considered a usurious transaction?

There are two scenarios for selling earnest money:

The first: The buyer pays the earnest money after the contract. If the sale is completed, the earnest money becomes part of the price; otherwise, it belongs to the seller. This scenario is impermissible for gold and silver due to the deferral of part of the price.

The second: The earnest money is paid before the contract along with a promise to purchase. In this case, if the purchase is not completed, the earnest money must be returned to the buyer. There is no harm in this scenario, even if the item sold is gold or silver, and this is what appears from the questioner's inquiry.