Comment on Rock Formation (title provided or enhanced by cataloger)


I have issue with this one part: "Explain that igneous rocks are those that are fire-made or volcanic rocks. They have small mineral pieces because they cooled quickly. Display trays of graphite so the students can see the large crystals in obsidian and explain that this looks like it contains pieces of glass. " As you know some igneous rocks are plutonic and have large crystals. Offer an example of a plutonic rock, too. Obsidian IS glass, not pieces of glass. Use obsidian without any impurities. What are the large crystals in it?? What is the graphite about?

Similar works

Full text


Digital Library for Earth System Education

Last time updated on 11/12/2013

This paper was published in Digital Library for Earth System Education.

Having an issue?

Is data on this page outdated, violates copyrights or anything else? Report the problem now and we will take corresponding actions after reviewing your request.