Dinamic Earth blog post; Gems and Minerals

In this blog post i will tell you all about Gems and Minerals. I learned some stuff from this website http://www.mnh.si.edu/earth/main_frames.html I hope you do too!

• Gems are measured by carats.
• One carat equals 0.2 g.
• The word carat comes from carob, a tree from the Mediterranean region.
  

How do Gems form?

• Gems form first when a volcano erupts dabrea and lava flies all over the place and as the Gems reached the surface, the volcano erupted. The fragments turned into a rock called kimberlite, in which the diamond is embedded.

What makes a Gem valuable?

• Size
• Beauty
  
• rarity
• and durability
• They are the BASIC reasons of what makes Gems valuable.

How do crystals become gems?
Nearly all 4,000 kinds of minerals can be cut down into gem stones, but only about 15 are commonly used for different types of jewelry.

1. They cut the crystal using a diamond saw.
   
2. They shape the crystal using a abrasive(rough) wheel.
3. Grind facets(polished plane surfaces of a cut gem) at precisely determined angels.
   
4. Polish the gem by pushing it against a wheel.
   

Where do gems come from?

• Gems have been found all over the world but these are the most common places they can be found:
• Colombia
• North America
• Brazil
  
• South Africa
  
• Madagascar
  
• Afghanistan
  
• Tanzania
• India
  
• Sri Lanka
• Burma
  
• Australia
  

Opals and Moonstones

• Opals are made of tiny spheres of silica.
  
• They scatter light which gives it its colors.
  
• It's made up of 6% to 10% water.
• Because of the water they can dry up and crack.
  
• The opal is the birth stone for October.
  
• Moonstones and sunstones belong to the feldspar family and they make up half of the earths crust.
  
• Occasionally, this common material forms a crystals that shimmers like a rainbow on a soap bubble.