Answer:
The correct answer is:
As a coloring (pigment) in makeup or paint. (d.)
Step-by-step explanation:
To answer this, let us explain the properties of the mineral described one after the other, and see how if fits into the production of the answer chosen.
1. Low hardness : A mineral with low hardness is one that does not have abrasive properties, it was specifically said of this property (can't scratch a penny), this property is ideal in a makeup product because since it is being applied on skin, abrasiveness and hardness as a property will cause injury to the skin on which it is applied, also if a hard or abrasive material is used for the production of paints, especially the ones used to coat materials to which contact will be made, there is a tendency of injuries being caused too.
2. Red color and streak: makeup and paint products are mostly used for finishing, and cosmetics, to create beauty and attraction, and colors play a big part in bringing about this, hence, the red color of the material will help accentuate this property of paints and makeups.
3. Low Specific gravity (density) : if a mineral for makeup has a high density, when used on surfaces (skin or other surfaces), it will be very difficult to wash of but a low density is essential to enhance washing off when needed and to reduced absorption into the epidermal layers of the skin.
4. Nonmetallic luster: a luster is a property that has to do with glowing, or shining. This is essential in makeup and paints, to improve outlook and finishing as described in 2 above.
5. Non-toxicity: this is most important in makeups and paints that will come in contact with skin and other biological surfaces. If the material is toxic, then contact with these surfaces will cause harmful effects on the individual.