Although we all know about the instant messenger joke, Mese is now considered to be a crystal of alien origin. It is found in stone at the a couple of different ranges of depths; go deep enough and you start finding not only Mese Crystals embedded in stone, but also whole compact Mese Blocks. When you dig a Crystals-in-stone object, you're actually cutting the individual crystals from the surrounding stone, while the large Mese Blocks are collected directly.
How it works now:
In practice, Mese now behaves similar to an ore, and looks like yellow chunks of material emedded in stone when found in the wild. When you dig one, you get something new instead of the block you dug. In order from left to right, they are:
default:stone_with_mese - looks like yellow chunks of crystal embedded into the stone. Found at depths of 128 meters and below. Drops 1 Mese Crystal on dig.
default:mese - looks like a yellow block engraved with the word "MESE". Found very deep underground (1024 meters and below). These should be reserved for recipes where one needs a whole lot of Mese in a compact space, though some people like to use them decoratively as well.
default:mese_crystal - looks sorta like a yellow brilliant-cut diamond. Obtained from digging the above stone_with_mese. These should be used to make tools and in recipes that would have used the original default:mese object.
default:mese_crystal_fragment - looks like a small shard of the above Crystal. These should be used in recipes where Mese is desired, but where a Crystal is logically "too much".
Crafting
To get Mese Crystal Fragments, place one Mese Crystal into the crafting grid. Yields 9 Fragments. Fragments, once broken from a Crystal, cannot be converted back, so don't waste 'em!
To get Mese Blocks (e.g. default:mese), fill the crafting grid with 9 Mese Crystals. Yields 1 block, which can then be split back into Crystals when needed. Old mods/recipes that depended on the original default:mese object can still use these Mese Blocks where the old black-on-yellow object was used before.
A Mese Pickaxe can be crafted from three Mese Crystals and two sticks, in the usual Pickaxe pattern.
The value of Mese
Modders should focus on using Mese Crystal Fragments for low-power/magic/value items such as coins, wires, etc.
Whole Mese Crystals as obtained by digging a Crystals-in-Stone object should be reserved for moderate-to-high power/magic/etc. recipes such as engines, magic staffs, etc. One Mese Crystal is equivalent in value, power, etc. to nine of the above fragments.
Mese Blocks should be reserved for high to insanely-powered/valued situations. There are, for example, a couple of mods that provide a sort of "compressed Mese" object. Such mods should probably use Mese Blocks either directly, or as feedstock for a new, even higher-valued compress recipe. Old mods whose recipes called for default:mese can still use these blocks, but they are now far more rare and far more expensive to obtain than before.
