Learn English – What’s the difference between ‘china’ and ‘porcelain’

That China means "from China" was pretty simple, much more interesting is from what porcelain came out:

Look up porcelain at Dictionary.com 1530s, from M.Fr. porcelaine, from It. porcellana "porcelain" (13c.), lit. "cowrie shell," the chinaware so called from resemblance to the shiny surface of the shells. The shell's name in Italian is from porcella "young sow," fem. of L. porcellus "young pig," dim. of porculus "piglet," dim. of porcus "pig."

So we have a shell (cowrie) that resemble a young sow. Then came this new material from China that resemble the shell material for smoothness and glossy, so they took the Italian name of the shell for the material. Curiously enough now the shell is called Ciprea in Italian, I never heard the word Porcellana in Italian in relation to any shell.