Meant to resemble an Astrolabe, a common symbol used to represent Hypatia.
History lesson time!
Hypatia of Alexandria was a philosopher, astronomer, and mathematician living in Egypt during the Roman Empire. For the Esoteric class named after her, I wanted the icon to be a symbol that represents who she was, which is why the Icon is an astrolabe. An astrolabe is an ancient astronomical tool that was used to measure the altitude of the stars and the sun, tell time, and calculate height. The Philosopher Hypatia is heavily associated with the tool because of her frequent teachings on how to construct, refine, improve upon, and use the tool. While not being the inventor of the tool, it is most heavily used as a symbol in discussions regarding Hypatia.
The Hypatia class is usually used with SCP articles focusing on scientific, philosophical, difficult-to-trace SCPs, often including subjects that react to being investigated.
If you want to learn more, some examples of articles that have used Hypatia as a class include:
SCP-8829
SCP-9073
SCP-9082
SCP-9272
SCP-9308
SCP-9495
SCP-9854
SCP-L106
SCP-L911