First of all, jewelry science needs to consume a lot of ore from mining, so you lose ore income.

Second, because there are jewels that have not been dug up, you have lost your herbal income.

Third, after the opening of WLK, jewelry drawings need to meet the requirements of local prestige before they can be purchased, and some prestige can only be obtained by changing shirts and brushing copies, and it can only be gradually improved through daily days, so the time for brushing prestige is wasted, and jewelry can't make money during this period.

To sum up, mining+jewelry is not as good as double mining.