1. FOSS Pebbles, Sand and Silt
Investigation 1
Set B

2. A gray, smooth rock that was once hot, liquid lava that came out of a volcano. (noun)
1. I have a piece of basalt in my rock collection.
2. I saw basalt when I was walking up the volcano.

3. A group of objects to be see, studied or kept together. (noun)
1. Museums have a collection of rocks for us to look at when we visit.
2. Toad has a funny collection of buttons on his jacket.

4. A piece of solid, often transparent material with shiny, flat surfaces that can be identified by its special shape or pattern. (noun)
1. I think that a crystal looks like a diamond.
2. I saw a bright crystal sticking out of the wall of the cave.

5. Not sharp or shiny. (adjective)
1. I can’t write with my pencil anymore because the tip is dull.
2. The dull gray rocks that wash up from the ocean have been smoothed by the water and sand.

6. A scientist who studies Earth and rocks. (noun)
1. A geologist came to my class to teach us about rocks.
2. I want to be a geologist and work on volcanoes when I grow up.

7. A building in which collections of scientific, historical or artistic value are studied and exhibited. (noun)
1. I went to see the dinosaur fossils at the museum.
2. There is a large collection of rocks at the Museum of Natural History.

8. Having sharp edges or corners. (adjective)
1. It is much easier to write with a pointed pencil.
2. Be careful! You can cut your hand if you hold the pointed edges of the rock too tightly.

9. Bumpy; not smooth (adjective)
1. I hit my head on the roof of the car when we drove down a bumpy road.
2. The surface of basalt, scoria and tuff feel bumpy.

10. A reddish, bubbly rock that was once the bubbly top of lava. (noun)
1. I bet that the lava was really hot before it became scoria.
2. The scoria I saw at the museum looks like hard red bubbles.

11. A light, soft rock that has ashes in it from the fires of a volcano
A light, soft rock that has ashes in it from the fires of a volcano. (noun)
1. The tuff I bought is as light as cotton.
2. How did the tuff get ashes in it before it became a rock?

12. Having lines of different shades or colors. (adjective)
1. A zebra is black and white striped.
2. Some striped rocks have lines of bright colors.

13. Flat, level; not rough. (adjective)
1. The smooth rock I found was in the river for a long time.
2. The skin of my apply has no bumps and is very smooth.