Posted by: tpsciencefun | September 17, 2010

Mock Rocks Are Back.

    Back by popular demand and the request of our 4th and 5th grade geologists, the recipe for these amazing, homemade, sedimentary rocks is now available!!  (Recipe below.  Adjust accordingly. Add any inorganic materials you might like to have  in your sedimentary rocks.)

Why do we make mock rocks in geology??  Well, it is a fun, hands-on way for our junior geologists to understand the dynamics of sedimentary rocks, how they  form and what they are made of.  Think of  a rock as a cookie.  Lots of different ingredients  are  mixed and mashed together, then heated so that the water evaporates, and the results are a solid rock/cookie all cemented and stuck together.  Of course, you can make our mock rocks over a short period of time whereas rock formations take thousands to millions of years to form.



1-Part One

Flour- 50ml

Salt-    25ml

Sand – 50ml

Oyster shells- pinch

Minerals (colored pebbles) – pinch

Alum- 1/8tsp

Plastic bag (for mixing)

2-Part Two

H2O–30ml (Use eye dropper if extra H20 is needed.)


A. One at a time, measure and put sediments in the bag.

B. Gently mix all the dry sediments together.


C. Measure H2O and pour into sediment bag in 10 ml increments.

D. Mix sediments using pressure and squeezing.

E. Shape sediments into sedimentary rocks.

D.Put sedimentary rocks in a warm, sunny spot to allow the H2O to evaporate and sediments  to cement together.

Ounces (U.S.) Milliliters
1.00 29.57
10.00 295.74
20.00 591.47


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