Ágata Joalharias is a jewellery business founded in 1981, with two shops in central Coimbra, Portugal. Its collections feature European design with a strong influence from Portuguese tradition, and production is primarily handcrafted in Portugal. The range includes jewellery, wedding and engagement rings, graduation rings, watches, gold and silver pieces, antiques, and items for personal adornment and home decoration. The company highlights its collections of engagement rings, wedding bands, and graduation rings, and represents a varied selection of watch brands.

Ágata Joalharias also provides services ranging from ear piercing to the maintenance of watches and jewellery. Its staff have completed training and examinations at the Portuguese Mint, and the business has been approved and appointed as official valuers, enabling it to offer a service certified by an official body. Customers can visit either the Rua Ferreira Borges shop or the Escadas de S. Tiago shop in Coimbra. Through its product selection and services, Ágata Joalharias aims to offer quality and glamour while helping customers find pieces suited to their tastes and occasions.