Thursday, May 9, 2013

geology question

These rocks were on my driveway. We got them from Colorusso as chopped stone, Hudson New York. The website says the stone they use is limestone but my geology book does not say limestone can be black. And there is a kind of special black limestone. http://en.wikipedia.org/wiki/Noir_Belge

That is not what this is.

You can see a trilobyte and some shell fossils in the stone. 

So, what kind of stone is this exactly? In Hudson, New York. Hard. Black. Many fossils. 




I think this is diamond quartz, with other stuff.


Flourite, from my collection



Gypsum, seems like


Mica, found many years ago



Amethyst


Monday, January 14, 2013

slinky experiment

In this video my dad is holding a slinky. When I say go, he drops it. The video is 4 seconds long and has 120 frames. We put ten frames (65 to 75) here as pictures. Ten frames would be about 1/2 second. In the 1/2 second in the pictures, the bottom of the slinky is not moving even as the top is falling. For a half second the bottom was standing still in the air with nothing holding it. Why? The bottom didn't know that my dad had let go of the top. 

video