http://skywalker.cochise.edu/wellerr/rocks/igrx/pumiceL.htm
Color: tan, gray, off-white
Texture: rough, bumpy, lots of holes
Density: less than water at first
Streak: ?
Hardness: medium hardness, brittle
Age: ?
Scent: none
Location Found: ?
Vinegar Test: no bubbles
How did this rock form?
This rock was formed when rock within a volcano became very hot and pressurized. It then was ejected from a volcano. This rock cooled very quickly as evidenced by the freezing of gas bubbles within the rock. This is an example of an igneous rock.
What is it made from?
This rock is made from volcanic lava which is composed mostly of silica and feldspar.
What don't you know about the rock yet?
I don't know where on Earth the rock was formed or how old it is. I also don't know if it leaves a streak on a streak plate or not. I would guess that the rock wouldn't bubble when exposed to acid since it isn't limestone or marble and doesn't contain calcium carbonate.
Errin,
ReplyDeleteThsi is great! Of course, students would not know as much.
Kelli