Book

The book lets you view the types of ores you have mined as well as the bosses you have defeated. it also shows how much of an ore or boss you have obtained and gives you additional, permanent levels depending on how much of that ore or boss you have defeated.

The level bonus for each type of ore or boss is as following: 3, 9, 27, 54, 99, with an efficiency bonus for reaching 99. In other words, when your total level increase from mining a specific ore is +99, you also get a bonus of mining that ore twice as quick. the range of ores or bosses you have to obtain to reach +99 level ranges from 30 million for stone to 100 for all bosses. Note that the harder it is to obtain an ore, the less you have to obtain to reach the maximum level bonus, but all bosses have to be defeated 100 times in order to reach the maximum level bonus.