Upgrading chances

On the right side of the screen, there is a button to upgrade your chances labelled "Upgrade chances". The chances refer to your chances to get a gem of given level between chipped and perfect. Hover it to get current, press it to upgrade them for gold. Each level past the first improves your chances on one or another level by 10% and costs 30 more gold than last one. The total cost of the tree from 100% Chipped to 30% Flawed/Normal/Flawless and 10% Perfect is 1000 gold.

Table for current chances and cost to upgrade to next level: