Tips and Tricks
Finish quests and you'll get gems as a reward when you complete them. Watch out those quests that involve breeding certain types of rare dragons.
You can also complete achievements for free gems. Check them out by tapping on the trophy icon and the achievement list will pop up. Keep in mind that achievements are a bit more grind-oriented than the quests.
check Dragon Codex witch requires you to build a collection of a certain group of dragons, and once you have that entire collection completed, you will earn free gems as a reward.
Check out the limited time events, as these are one of the best ways in the entire game to earn large amounts of free gems.
Go to the Mystic Cave and the Pirate Ship after you unlock them and explore for a good shot at free gems.