Question

question 4 of 10
which of the following would be a clue that a rock is igneous?
choose one option
a it has crystals.
b it has a complete fossil in it.
c it has bands.
d it is very soft.

Explanation:

• Option A: Igneous rocks form from cooled magma/lava, and mineral crystals can form as they cool (e.g., granite has crystals).
• Option B: Fossils are in sedimentary rocks (formed from sediment, where organisms can be buried), not igneous.
• Option C: Bands are typical of metamorphic rocks (formed under heat/pressure, causing layering), not igneous.
• Option D: Igneous rocks like granite are hard; soft rocks are more likely sedimentary (e.g., shale) or some metamorphic, but not a clue for igneous.

Answer:

A. It has crystals.