Question

Rhodochrosite in hand specimen is most likely to be confused with certain varieties of:

• A. Wollastonite
• B. Orthoclase
• C. Gypsum
• D. Biotite

Hint:

Always confirm rhodochrosite by acid reaction (effervesces in cold HCl) and higher specific gravity, which distinguishes it from feldspar.

Answer 1

The Correct Option is B

Step 1: Properties of Rhodochrosite.
Rhodochrosite (MnCO$_3$) is a carbonate mineral, typically pink to rose-red in color, with vitreous luster and perfect cleavage.

Step 2: Confusing mineral.
Orthoclase feldspar can also occur in pink varieties (commonly called "pink feldspar"), visually resembling rhodochrosite in hand specimen.

Step 3: Why not the others?
- Wollastonite: usually white/gray fibrous. - Gypsum: softer, transparent/white. - Biotite: dark brown/black mica.

Final Answer:
\[ \boxed{\text{Orthoclase}} \]