As someone who loves rocks and minerals, finding a new sample is super exciting. Geologists use some very basic tools to help them determine the name of a rock or a mineral. Identifying a sample starts with discovering the names of the mineral or minerals, in the case of rocks.
The tests that geologist use for minerals include:
Examination: Use a hand magnifier to determine luster, cleavage, shape and color of a sample. A rock hammer is sometimes helpful in determining cleavage and color if you don’t mind breaking your sample.
Hardness: Use the Mohs Hardness Scale, old pre-1982 pennies, paper clips, glass plates, and your own fingernail to determine the hardness of your sample.
Streak: Use white and black streak plates to determine the streak color (the color of a mineral powder) to help make an identification.
Fizz Test: Use fresh lemon juice or vinegar on a fresh surface of your sample. Hydrochloric acid is the most common acid used by geologist but it is not easy to purchase and lemon juice and vinegar are a better choice for children. Since lemon juice and vinegar are a weaker acid, use a paper clip to scratch the surface of the sample to removed any weathered outer layer. The lemon juice or vinegar will react best on a fresh sample area. Remember, if your sample fizzes, it is made of calcite!
Mini Me Geology’s new Rock and Mineral Testing Kit has everything you need to get started with identifying your samples.
Each Kit Includes:
- Mini Me Geology Hand Lens with 3x and 6x magnification helps you see your samples closely,
- Pre-1982 age penny,
- Large metal paperclip,
- Glass plate,
- White streak plate,
- Black streak plate,
- Information cards that teach you about the Mohs Hardness Scale and how to perform each test. These cards include instructions for hardness testing, explain how to perform the streak test and how to focus your new hand lens so you can see the details of your rocks and minerals.
As you gather your data from testing each sample, a flow chart is a helpful tool to find the final identity. Mini Me Geology has free basic identification flow charts that you can download and print. For advanced studies, we also offer identification posters which explain the properties 10 of the most popular minerals. We also have posters for igneous rocks, sedimentary rocks, and metamorphic rocks.
If you need help testing your samples, you can always contact us and our geologist will help you!