This is quite different from the hundreds of other crosses on this website.
The photo on the right was kindly sent to us by a lady who says the piece might be from Portugal. The horizontal beam is 2.5cm (1") and the vertical shaft is 4 cm (1½"). The cross is voided and inlaid with mineral, coral, possibly abalone shell.
There are similarities with the Thor Cross, a popular favourite of Neopagans, but the mosaic of inlaid seashells are encased in brass alloy rather than a basic metal such as iron, copper, silver, gold or a rare -ium.
So what is it? See Trondheim Cross.