The beautiful mugs by hejdesign are so good looking and Summer gorgeous. The material of the mugs is grey stoneware with lava. Approximately, half of the mug (the upper part) is glazed. This gives you an idea of how the clay react with and without glaze. It's a pretty contrast. The small lava spots in the clay are visually expressed in a different way in the glaze than in the raw stoneware at the bottom of the cup. The colours are beautiful and can match nicely together. Behind the brand hejdesign is Danish ceramicist Rikke Wulff, who hand makes all her ceramics in her workshop on Bornholm, Denmark.