The order of the tools is the following
And from silver on, it’s 3 hits.
Before the update, gems were easier to find, but fossils were harder, so it kinda made up.
Now after the update, you can find silver, gold and titanium pretty easily, plus fossil, and gems are not that easy anymore. So it’s not as easy anymore to go for the gem tools.
Plus the gem tools have more durability, apart from the fact, grapples act differently according to the materials.