User blog comment:DancePowderer/Deus Ex Lacrima/@comment-7418318-20140209012913

LCD = Lacrima Crystal Diode? Or replace that with LLD = Liquid Lacrima Diode :P

I think Lacrima is an over-term for any kind of magic stone, whether it was created out of magic or "just" has the ability to hold or manipulate magic. Just like the word "gems" encompases a plentytude of different stones, some of them crystaline, some of them not.

So Dragon Lacrima could be a crystalization of their magical powers (that something like this is possible is shown by Magnolia and the Exceeds being turned into Lacrima in the Edolas arc), while energy storage Lacrima are just some gem-stones that happen to have the ability to store magic power, while yet others are able to focus or redirect magical streams (like the inner workings of Jupiter).

As for the specific examples of the tanning and music lacrima: We don't know what the lacrima really do. It could be that they are just the energy-source with other machinery doing to "actual" work. Just like the SE-Plug cars are actual cars in all their workings like E-Cars, but instead of a battery, they suck the energy from a mage.