Question

Carnallite is the mineral of:
A. Na
B. Ca
C. Mg
D. none of the above.

Answer 1

Hint: It is a rare double chloride mineral that forms under specific conditions. It is a major source of potash.
Complete step-by-step solution:
To answer this question, at first, we have to know where the carnallite compounds are found and its composition. Carnallite occurs with different chloride minerals along with the higher layers of marine salt deposits.The mineral is located basically with the northern German salt deposits; and additionally in Spain,Tunisia, and the southwestern United States. Carnallite is a soft, white, and halide mineral.
Carnallite is a halide mineral a hydrated potassium magnesium chloride. It is variably colored yellow to white, reddish or blue. It takes place with a series of potassium and magnesium evaporite. It is an uncommon double chloride mineral that bureaucracy below particular conditions. It is a major supply of potash.
The ore of sodium is rock salt. The sodium found in this ore is sodium chloride. The chemical formulation of the ore is $NaCl$.
Many minerals are composed of calcium. Calcium minerals are very common and may be mined anywhere. It is mainly acquired from limestone, dolomite and gypsum. Common calcium-bearing minerals consist of anhydrite (calcium sulfate), gypsum (hydrated calcium sulfate), and aragonite or calcite (calcium carbonate).
Thus, the right answer is option C. i.e. Mg.
Note: It is mostly used in fertilizers. It is a main source of potash. Only sylvite outranks carnallite's importance in potash production.