Question

Which mineral has a metallic luster, does not react with hydrochloric acid, and has a hardness of 6?

Mineral Color Streak Reacts with hydrochloric acid Hardness
Golden Mineral Sample. Text that reads: Gold Golden yellow Yellow No 2.5 – 3
Shiny Mineral Sample. Text that reads: Pyrite. Yellowish gray to gray Black No 6 – 6.5
Yellow Mineral Sample. Text that reads: Sulfur. Bright yellow to yellow-brown White No 1.5 – 2.5
Light green Mineral Sample. Text that reads: Calcite. Colorless, white, yellow, brown, orange, pink, red, purple, blue, green, gray, black White Yes 3
A.
Pyrite
B.
Gold
C.
Calcite
D.
Sulfur

Answer 1

A. Pyrite

Pyrite has a metallic luster, does not react with HCl, and has a hardness of about 6 (6–6.5). Gold is much softer (2.5–3), calcite reacts with HCl, and sulfur is very soft (1.5–2.5).