Garnet is 6.5-7.5 on the hardness scale
As a big rock nerd, please don't disrespect Moh's Scale by relating a beautiful mineral with all of Hathaway's impurities and imperfections just because they share the same name. Hathaway sucks. The mineral is awesome. The gemstone is very pretty and holds great value. Hathaway is ugly and holds little to less value. JAG.
He comes to the roster deeply flawed and bringing little to no worth. He is not of gemstone quality (which are rare), he is the common type - deeply flawed and imbued with imperfections. Perfect for a 4th line role (but completely obsolete on this Flyers team). Garnet is the type of player you can find littered all across the NHL, most notably, within your own franchise's pipelines as he does not bring any unique abilities the average NHLer lacks. Coincidentally enough, the mineral is very common and found dispersed in many different types of rock formations across Earth that any Joe-Shmoe can find on a walkabout.
If the Flyers/Torts are unable to grind him into a fine powder and use his abrasiveness effectively (wooo! BSB so gritty) then this garnet is truly dull and holds little value so the Flyers need to move on from him by this year's deadline, or sooner.
I love that they overpaid his salary, too. Like a desperate merchant overpaying for common goods simply because they don't want to search elsewhere for a better deal or look from within to see what resources are already available.