Crystals

Obtaining Litherite

The first crystal, Litherite, can easily be obtained by combining emeralds, ender pearls and quartz. This recipe is just a regular crafting recipe and can be viewed in JEI. There are several recipes associated with crafting litherite and you'll most likely want to aim for the one that uses 4 ender pearls, and 4 quartz in order to get the most out of your emeralds.

Crystals

One of the first things you are probably going to want to mine is more Crystals. This happens to also be the way to obtain the next tier of crystal. To mine Erodium crystal you will need a tier 1 mine or above. Each tier crystal is obtained by the previous tier miner. The only crystals that have different requirements for mining are Nanorite and Xerothium crystals which, in addition to the previous tier miner, you'll need to have that miner in the End dimension. 

Mica

You can obtain mica using the Resource Miner(Multi Miners->Resource Miner) or the Rocky Resource Miner(Resource Miners->Rocky Resource) programs. Mica does not have a lens focus which means there is no lens type that will improve its mining rates. The best way to obtain it is using the Rocky Resource Miner program.