Irish Bronze Cross Brooch & Green Agate Stones Stunning Irish Bronze Cross Brooch with Green Agate Stones. Made by the renowned Astra. Astra are a sterling silver jewelry company based in Kilkenny since 1988 and have developed their range over a number of years. Crafted from Bronze detailing the famous Irish Trinity Knot and a Emerald Isle Green Agate Stone in the center styled similar to a shield. Presented in a lovely gift box. This piece measures approximately 1.5" x 1.5". Designed in Ireland and delivered from Ireland to the US within 6-9 Days plus free Irish gift with every purchase.