Indice de rocas ( rocks photographs ).

Rock Atlas

Hand specimens and rocks under the microscope

Rocks visually and microphotographs of rocks

Carlos Dorronsoro

Igneous rocks

 

Plutonic rocks
  

only with potassium feldspars

 <10% plagioclase

with feldspars

 without feldspars

 % of plagioclase versus total feldspars

 

 

 

 10-35

 35-65

 65-90

 >90

          

 with quartz

>20% y <60%

  

 without quartz

<20%< y >5%

  

Quartz

sienite

alkaline

Quartz

sienite

Quartz

monzonite

Quartz monzo diorite

Quartz monzo gabbro

Quartzdiorite

Quartz gabbro

  

 without quartz

<5% y >0%

  

Monzo diorite

Monzo gabbro

 without quartz <0%

with feldspathoids>10%

      

 

 

Volcanics
  

only with potassium feldspars

whit feldspars

 without feldspars

 % of plagioclase versus total feldspars

 10-35

 35-65

  >65
         

 with quartz

>20% y <60%

  

alkaline rhyolite

 

 with quartz

<20%< y >5%

  

Quartz trachyte alkaline

Quartz trachyte

Quartz latite

Andesites Basalts
         

 without quartz

<5% y >0%

Trachyte alkaline

 without quartz <0%

with feldspathoids >10%

  

 

 

PYROCLASTICS

 

Subvolcanics (o hypabyssals)

 

Sedimentary rocks sedimentarias

Detritals

   

Chemicals

     

Metamorphic rocs

          

 

The vast majority of the photographs shown in this selection have been taken from samples belonging to a collection of visual rock specimens from Ward's Natural Science Establishment Inc. P O Box 1712, Rochester, New York 14603, USA (and from microscopic preparations, or thin sections, obtained in our laboratories)..

References

 

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