Astoria makes this cute but fabulous Daivd Egg shell fountain pen out of duck egg shells. It is slightly bluish in colour as the minute oxidation process on calcium took place. It has a screwed-on cap which gives it a good grip if you wanted to pose the cap at the back of barrel during writing due to its size.
The nib is 18kt white gold and comes in beautiful leather black box. This pen is also available in Rollerball.