MINERALS AND CRYSTALS 189 



no granite, and granite is very precious to man as a 

 building stone. Of it we build walls, bridges, 

 churches and great public buildings. 



It is not only when they cool in a massive rock 

 like granite that the different minerals give place 

 to each other. When the rain-drops force their 

 way through the rocks, they take up more than one 

 kind of mineral atoms. Now when they come to 

 the open space, it often happens that each kind of 

 mineral wants to crystallize and each must grow 

 into a crystal of its own shape. So they have to 

 divide up the room. It seems strange, does it not, 

 to think of crystals dividing fairly the space they 

 are to live and grow in, just as children divide up 

 their play room among themselves so each may have 

 a corner to himself. 



How do the crystals know about the room each 

 shall need, and how they will best fit in together? 

 Ah, that is one of God's beautiful and wonderful 

 mysteries. He has given to the rocks and the 

 different minerals in the rocks certain laws. These 

 laws the rock which you look upon as dead, obeys. 

 Whenever there is a chance to crystallize, the 

 minerals will do so, and under whatever conditions 

 they find themselves they do the best they can. 

 When there is room for each to grow by itself, 

 these minerals make of themselves such beautiful 

 crystals of such wonderful shapes that when they 

 are found they are treasured as gems, and people go 

 a great distance to visit the museums where they 

 are kept. But when they are crowded God's laws 

 are still obeyed, whether different crystals form to- 



