Hi,

Very nice set! I believe they were made by Belleek china, Ireland – quite collectible. I have seen similar tea cups but not the mug, so I would put the value at $20-$30 if I were trying to sell them. Hope that helps!

Company History:
https://en.wikipedia.org/wiki/Belleek_Pottery

http://www.ebay.com/itm/Belleek-Ireland-Fine-Porcelain-Basketweave-Shamrock-4-mug-Twig-Hdl-brown-Mark-/361563020408?hash=item542ed5dc78:g:Xx8AAOSwfC9XPM9g

http://www.ebay.com/itm/Belleek-Co-Ireland-Woven-Shamrock-Coffee-Cup-Mug-4-Tall-/152105664047?hash=item236a343e2f:g:3jwAAOSwagdXSGIH