So...I noticed this with the last few dragons obtained through mining. The Glacial Dragon will be unable to be mined in about 2 days and I am currently at 230/275 Glacial Stones. With the last dragon, the Spelunking Dragon, I was also about 10 or 15 materials short. Now I know how to do the mine correctly, and I use every bomb, don't waste them etc, and I play every day. Yet I keep having this problem. If they were available just a few days longer, they would be more obtainable. Does anyone else experience this?