Quartz tube (for chlorination) with quartz boat (in front and on the right)
The quartz tube and quartz boat are fairly expensive (we only have one quartz tube right now!). Quartz is in many ways different than Pyrex from which most of the other equipment is made. It is more heat resistant (m.p. ~1400 oC for quartz, m.p. ~560 oC for Pyrex) and has a lower thermal expansion coefficient as well. While it permits to run reactions at higher temperatures, there are also several important points to consider when it comes to working with quartz:
1. Always use gloves when you touch the quartz tube. Your skin desorbs alkali metals that cause the quartz to crystallize (--- > cracking upon heating!). Make sure that you clean the quartz tube and the boat immediately when you are done with the reaction. Many impurities i.e., alkali cause damage to quartz. When you set up the tube, make sure that you support it properly.
2. After the reaction was completed, the tube and the boat have to be cleaned immediately. This will make it easier and also reduce the damage to the tube and the boat.