It is common knowledge that diamonds are the hardest material on Earth. However, defining the softest material is not as straightforward.
Softness refers to a substance’s tendency to deform (and remain deformed) when applying pressure.
The classical test for measuring hardness and softness is the Mohs test. In this test, two materials are rubbed against each other to determine which one scratches the other. According to this test, talc—a mineral composed of hydrated magnesium silicate—defines the softest point on the 1–10 Mohs scale, making it the softest known mineral.

Talc is a naturally occurring mineral mined from the Earth and consists of magnesium, silicon, oxygen, and hydrogen. Chemically, talc is a hydrous magnesium silicate. Its chemical formula is Mg₃Si₄O₁₀(OH)₂.
The term “talc” can refer to both the mineral itself and cosmetic products that contain talc in varying proportions, often mixed with corn starch. As a metamorphic mineral, talc is processed into a fine white powder, commonly known as talcum powder, which has excellent absorption properties for both moisture and oils.
Name: Lokendra Singh
Department: Chemistry JEE(Foundation)
Narayana Jaipur Center (NIHQ)