Transcript Minerals, Crystals and Rocks

A Recipe for Rocks
What is the
difference between
a mineral, a crystal,
a rock and a gem?
 An element or a
compound that
occurs naturally,
but is abiotic (non
living).
 “The ingredients
of rocks”
 A solid made up
of molecules
arranged in a very
specific pattern.
 “Chunks of
minerals in rocks”
 A hard and
compact mixture
of minerals.
 “A smallish chunk
of earth.”
1. PLEASE WORK CAREFULLY and try not to spill the Epsom salt.
2. Put on a pair of goggles find a Petri dish and a post it note.
3. Write your names, class period and “Fast Cooling” or “Slow Cooling” on
4.
5.
6.
7.
8.
the post it and place it on the bottom of the Petri dish.
Take a pipette (eye dropper) and add just enough of the Epsom salt
solution to cover the bottom of the Petri dish.
Take a small pinch of the Epsom salt crystals and sprinkle them around
your Petri dish to “seed” your crystals.
If the crystals are fast cooling crystals carefully place them in the
refrigerator.
If the crystals are slow cooling crystals carefully place them on the
counter by the window.
Be sure to have one fast cooling and one slow cooling crystal dish per
group.
2 5
3 4
1
Granite
Rhyolite
Obsidian
Gabbro
Basalt
Continental
Crust
(Mountains)
Continental
Crust
(Around
Volcanoes)
Rock cools too
quickly to
form crystals
(Around
Volcanoes)
Oceanic Crust
Oceanic Crust
Used for
countertops
Used for spear
heads and
scalpels
Makes up sea
stacks and the
Columbia
River George
1.
There is a good chance that some of your Epsom salt
solution is still liquid so handle the Petri dishes carefully.
2. Find your two Petri dishes and compare the size of the
crystals.
3. Which has bigger crystals fast cooling or slow cooling?
4. Take a look at the rocks. Which have the bigger crystals.
Make the connection.
5. Sketch your crystals (or a different group’s crystals if your
crystals didn’t work out) on the table on your lab.
6. When it is time to clean up carefully take off the post it
note and then place the Petri dish with the crystals in the
sink of the demonstration table up front.
2 5
3 4
1
Granite
Rhyolite
Obsidian
Gabbro
Basalt
Intrusive
Extrusive
Extrusive
Intrusive
Extrusive
Continental
Crust
(Mountains)
Continental
Crust
(Around
Volcanoes)
Rock cools too
quickly to
form crystals
(Around
Volcanoes)
Oceanic Crust
Oceanic Crust
Used for
countertops
Used for spear
heads and
scalpels
Makes up sea
stacks and the
Columbia
River Gorge
 Discovered in 2000 by a mining






company in Chihauhua , Mexico
Exposure time for humans
300 meters (980 ft) below ground
is about 10 minutes
(under the Cave of Swords)
without protection.
Gypsum (CaSO4) Crystals
58 C (136 F)
90-99% humidity
500,000 years to form
Largest crystal:
12 m (39 ft) long
4 m (13 ft) in diameter
55 tons