There are three Types of stones, All of which are necessary for the acquisition and improvement of buildings and facilities.

These include Diamonds, Emeralds and Rubies, as well as Pearls (you can buy for real money).

You can earn Emeralds by giving Tzadoko. For every 10 coins - 1 emerald.

Rubies can be obtained by performing daily quests.

Diamonds can be obtained by completing quests on an article.

At the exchange office, You need Pearls to change one type of stone for a diferent type of stone.