How to Tell the Difference Between Talc & Gypsum

There are several ways to tell the difference between rocks and minerals.
••• rocks image by Mat Hayward from

Rocks and minerals all have different characteristics, including hardness and luster. The Mohs Hardness Scale is the primary scale that tests a rock’s hardness by how easily it can be scratched. Diamond has a score of 10 on the hardness scale, which is the highest a mineral can obtain. Talc has a score of 1, and gypsum has a score of 2, which makes these two minerals similar and difficult to differentiate between.

    Feel both pieces of rock for how slippery they are. If the rock is slippery, it may be talc. If the rock isn’t slippery it may be gypsum.

    Fragment pieces of each rock with your fingernail. If cleavage fragments fall off and are tiny, the specimen is talc. Cleavage on talc is perfect. Cleavage is the quality of a split along defined planes of a rock or mineral. In this case, you would be splitting the rock with your fingernail.

    Scratch each piece of rock. If powder falls off and doesn’t feel slippery or greasy, it’s gypsum.

    Check the colors of each. Talc will have a gray, white, green or silver color to it. It can also have a dull, pearly or greasy luster. Gypsum can be colorless, white and gray with yellow, red and brown shades to it. Gypsum can also have a pearly luster to it.

Related Articles

How to Identify Valuable Rocks
How to Identify Unpolished Agates
How to Identify Basalt
Can Scratches Be Polished Out of a Sapphire Crystal?
How to Identify Green Semiprecious Stones
How to Identify Clear Quartz Crystal
How to Find Agates
How to Identify Semiprecious Stones
List of the Minerals Found in the State of Washington
What is a Sardonyx?
How to Tell if a Rock Is a Meteorite?
The Different Kinds of Missouri Stone Used for Flint...
Physical Properties of Calcite & Quartz
Places to Find Flintstones
How to Identify Rough Gem Stones
How to Do a Streak Test With Rocks
Why Does Basalt Weather Faster Than Granite?
What Are the Differences Between the Minerals Calcite...
Where Is the Mineral Topaz Found?
How to Tell Fool's Gold from Real Gold

Dont Go!

We Have More Great Sciencing Articles!