Sword of Light

To commemorate the golden jubilee of the 1916 Rising, the Dublin Assay Office designed an extra mark that it placed on items stamped in Ireland in 1966.
It was called an Cladheamh Solais (The Sword of Light). This mark was stamped in addition to the existing hallmarks used by the Assay Office on all Irish made articles of gold and silver other than jewellery and watch cases assayed during the year 1966.
I spotted it the other day on a chalice used at Mass. This is a close-up of the hallmarks on it.
The extra pic is a wider shot.