The features of this crystal are outstanding.

It´s a Hematoid Cathedral quartz crystal in its complete formation. This type of formation is also called Artichoke.
It´s double terminated  and this is so because this crystal at some point of its evolution, by natural causes broke free from its matrix and started to heal itself (self healed crystal), by doing this grew various completelly formed terminations on that end making it not only double terminated but also an Alien quartz.
Another amazing and very rare feature to find on a crystal is that on the one termination it has growth inhibition (so it seems but not sure).
It has split growth on the prism faces, but one half of the crystal tip seems to be cut away. It is very visible that there´s half of a cap on the termination and it has an irregular shape where it stopped growing.
It is likely that the tip was covered by a growth-inhibiting material (probably hematite) on the now smaller half of the crystal,  just like it has now Hematite on the bigger half of the crystal.
Later the hematite got dissolved and the growth resumed, although it´s still visible some traces of Hematite that was probably what caused the growh inhibition to happen.
The same could happen to the other half of the tip that it´s still there, because it has Hematite on top, it could be that this Hematite would get dissolved and another layer would be formed like the one that already exists or if the Hematite would not get dissolved the crystal would continue to grow enveloping the Hematite and forming a phantom.

This crystal comes from Boekenhouthoek, Mpumalanga province of South Africa.