Site hosted by Angelfire.com: Build your free website today!

Rocks In My Head

Blog Tools
Edit your Blog
Build a Blog
RSS Feed
View Profile
« April 2010 »
S M T W T F S
1 2 3
4 5 6 7 8 9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30
Entries by Topic
All topics  «
geology et al
some days are pretty good
My own link
Rock Shop
You are not logged in. Log in
04/29/10
andesite
I think I will blog now and then about rocks as opposed to minerals.  Rocks are aggregates of minerals, classified according to how they were formed (igneous, sedimentary, metamorphic).  These can be subdivided into other classifications, such as particle size.  Formation of rocks is a gradual process and one type sort of morphs into another.  Selecting reference points is  arbitrary; however, it has been done and there are a finite number of rock types, according to petrologists.  Usually in books, igneous rocks are considered first.  The first one on that list is andesite, named for the Andes mountains.  It is an intermediate crystalline rock, consisting mainly of plagioclase feldspar.  There is also a mineral called andesite, which confuses matters.

Posted by oh5/ojhoff at 2:37 PM CDT
Post Comment | Permalink | Share This Post

View Latest Entries