[member="Jacen Clanstrider"],
Lightsabers can be made for many different reasons.
Some people make them to aid in the use of various Lightsaber Forms *I can link you to them if you would like*, for sentimental reasons, or because they need to be specially made to be specifically built for them as a creature with a size difference, or to act in a different way.
This link here will provide you all the information about all known crystals in Canon, or created on the site. Many of the effects that can be used are allowed, while others, like the mentioned lava dripping crystal, are frowned upon.
A lot of the crystals that have game mechanics, like the Life Drain Crystal, which are looked very poorly on, and most of the time will not pass through the factory as per a unwritten "Fairness" among people who can use lightsabers.
For a reference,
I created my own lightsaber that has a lot of special functions such as Dual-phase, Force ignition, Pressure grips, and even a special blade type that matches the infamous Darksaber. In the sub that I linked for you, there are many links to the Wiki lightsaber sub, and much more.
If you have any more questions, my PM box is always open, or you can ask here.
Cheers!
