OF EDUCATION 79 



twelve faces. The ends of the pyramids are very 

 sharp. Zircon is the hardest mineral we have ever 

 studied, its degree of hardness being between seven 

 and eight. My specimens are about seven and three- 

 quarters. All sides of crystals are very shiny and 

 smooth. They are prisms with a pyramid at each 

 end, if the crystals are perfect. 



"The color of zircon is a light chocolate brown, 

 but sometimes it is white and reddish colored. It is 

 spotted light and dark brown in some places. It is 

 composed of zirconium, oxygen, and silicon. In one 

 hundred grains of zircon, there are forty-nine grains 

 of zirconium, thirty-five of oxygen, and sixteen of 

 silicon. Zirconium is a very beautiful metal resem- 

 bling silver in color, and is five times as valuable as 

 gold, being worth fifteen hundred dollars a pound. 

 There has as yet been no use put to it, but sometime 

 it may be very useful. Oxygen is a very useful gas, 

 as it keeps all animals alive, and is in a great many 

 minerals, in all shells and limestone, and a great 

 many other things. Silicon is not a metal, but it is 

 in a great many different minerals. It is very rare, 

 and difficult to extract from the rocks. Zircon is 

 used in jewelry, being sometimes passed off for dia- 

 monds when of a white color. When it is of a reddish 

 color, it is called hyacinth. 



' ' Zircon is found in the iVdirondack Mountains in 



