Auronia

Auronia’s designer lets you set the metal (yellow, white or rose gold, or platinum), the band width and finish, and add a free engraving before you order. Diamond options are GIA-certified, and the studio points to a high palladium content in its white gold for durability.

Returns run 30 days and every ring carries a lifetime warranty. FedEx and UPS are listed as the shipping carriers, with free shipping advertised, though the page does not spell out Swiss delivery in detail, so it is worth confirming at checkout.