Welcome! By picking this book up you've already taken your first step to understanding Ender Matter - many people believe that Ender Matter is but a fictional material located only within the bounds of your imagination, however you've crossed the bounds of ignorance and are beginning your way towards making the next tier of tools from diamonds. Now, to begin with, we must first understand what ender matter is:
Ender matter is a form of magical matter that slowly gathers inside the eyes of endermen. Now, you may be saying to yourself "Ooh- magic. I'm familiar with this, all you have to do is read the incantations off a book-". However, this magic is not any kind that can be evoked by simply uttering a few words; this magic is a sort that feeds off directly from darkness itself, the sort of darkness which covered the earth before the Being. Because this magic stemmed from darkness, when the Being came into existence, much of the existing darkness was pushed into the end, causing compaction and compressing of the aforementioned dark magic, which created ender matter.
"But why does ender matter gather inside the eyes of the endermen?", you may ask. The manifestation of dark matter inside endermen eyes is not the work of dark magic or another god, it is, in fact, a result effected by the process of evolution. You see, being forced into slavery by the ender-dragon denied endermen access to all magical (the endermen dwell off magic) supplements bar ender-stone, obsidian, ender-crystals, and darkness. Now, firstly, ender-stone is extremely magic-scarce, and is not easily digested inside an ender-man. Obsidian, on the other hand, while moderately magic-dense, is extremely hard to digest within the body of an enderman, again. Ender-crystals are extremely magic-dense and consequently, when consumed, explode. The obvious choice for a magical supplement would be darkness - the darkness contains the type of magic that the Enderman needs, and is extremely easily digested.
Now, those familiar with overworld-creature anatomy would automatically assume that endermen would consume food (or in this situation, magic) through their mouth, however this has not happened to be the case. Firstly, endermen don't have mouths. They have been deprived of mouths by the ender-dragon ever since they have been forced into slavery. What over-world anatomists classify as the mouth of the endermen are actually the vocal cords and the remnants of the enderman's jaw. Secondly, dark magic cannot be perceived by any sense other than the eye - it is only the eye which can perceive the existence of darkness. Thus, the endermen consume darkness through their eyes, and as such dark magic will slowly gather in their eyes.
Now, I'm sure there are quite a few of you out there who have slain an enderman or two, and received its eye (the ender pearl). Now this eye can be used for two purposes: One, to serve as the magical component in an "Eye of Ender" (Not an enderman's eye) which combines the flight powers of a Blaze with the darkness-detecting powers of an ender eye that can be used to find an anomaly in the time-space fabric of the universe that leads into the End, or secondly, to create Ender Diamonds, one of the most powerful materials in the world.
Ender Diamonds fuse the pinnacle of the light of the overworld (a diamond) with the manifestation of darkness in the End (ender eye). As such, when combined, the two substances will be constantly colliding together to cancel each other out, however this process can not be observed physically, as it happens to be entirely magical. When disturbed PHYSICALLY, the substances will slowly merge together to create a neutral vacuum (there are equal portions of dark and light located throughout the diamond) - that is to say, emptiness, as the darkness cancels out the light. As such, though an ender diamond is infinitely powerful magically, it is finitely powerful physically. Now, because of the constant magical collision occurring within the material, it is impossible to attach a regular wooden stick (which is only found in the overworld) to the material without imbalancing the Ender Diamond, so while it is possible to create Ender tools using wooden sticks, the tools will not use the full potential of the Ender Diamond, and the imbalance will cause the tool to deplete rapidly in the Overworld, due to a lack of darkness to cancel out the light, but repair itself in the End (this may be desirable under certain circumstances). However, if we use a stick of obsidian (a material that is both consisting of a moderate amount of light and a moderate amount of dark), then our tool will deplete less quickly within either realm. As such, the general consensus is that obsidian sticks and ender diamonds should be used to create standard ender tools.
--TO BE CONTINUED AS MORE INFORMATION IS GATHERED--