In this quick and inexpensive tutorial, we are going to show you how to make an Outrageous Opal Expedition. These excavations are super easy to make and are a great teaching resource to include in your next lesson or discussion about opals, gemstones, geology, and more.


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Plaster of Paris


Mixing Bowl

Wooden spoon

Measuring cups

Popsicle sticks – Popsicle sticks are inexpensive, readily available, and make great excavation tools.

Safety goggles or glasses – You we need to provide or borrow a set for each student.

Optional – Brushes and magnifying glasses.

Empty Altoids Tin

Rough opals - There are many varieties of opals and you can easily find inexpensive bags of rough opals online to use in this excavation activity. 


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  1. Place some opals in the tin. If the opals are too large, place a few in an old sock and while wearing safety goggles, gently tap the opals. Opals are brittle and will easily break. Dispose of the sock as the little shards of opal are very sharp. 
  2. Mix 1 cups sand with 1/3 cup Plaster of Paris.
  3. Add 1/3 cup of water and mix until you have a pancake batter consistency.
  4. Pour the mixture over the opals.
  5. Place the Outrageous Opal Expedition in front of a fan overnight until it is completely dry.
  6. Distribute the excavation, excavation tools, and safety goggles to your Excavating Adventurer and have fun watching them dig in and discover the awesome opals you have hidden inside.


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