Eggs, with their shells of calcium carbonate, form pockets in which crystals can grow, if the appropriate solution is added to them. How amazing the effect will be depends on your skill with eggs.

A culinary student created huge chocolate geodes in which he grew beautiful rock candy crystals. ... It took six months for them to grow these sugar crystals inside 12 chocolate eggs. Mashable ...

A geode is the inside of a rock that is lined with crystals. Bakers and bakeries are decorating cookies to look like geodes, often with rock candy and edible glitter.

Taken by themselves, geodes are gorgeous, with the insides lined with crystals that add a sense of beauty and wonder to the rocks, and they become even more amazing when they are dinosaur eggs, as ...