Random Riddle: Physics and Chemistry

If you like your Physics and you like your Chemistry, You will find this puzzle, as easy as can be. Firstly, from a glass of milk, take what is good for bones. Second, take the metal used to glaze pottery with pretty tones. Thirdly, you might eat me to get your innards on a slide. Last I am a diode in a ‘crystal-set’ just look inside. Now put us all together, and thus what can be seen?

A great big head? : A large white moth? : A vegetable that’s green?

What am I?

Riddle