Rocks & Minerals trivia

Rocks & Minerals Mini Quiz

Test your knowledge with these top questions!

Question 1

Which mineral fizzes readily when dilute hydrochloric acid touches a fresh surface?

Calcite releases carbon dioxide bubbles because acid reacts with its calcium carbonate.

Question 2

Which principal ore pair supplies titanium for durable white pigments?

Titanium dioxide scatters light strongly, giving paint, paper, and plastics an opaque, durable white.

Question 3

Rapidly cooled lava creates which glassy igneous rock?

Obsidian forms when silica-rich lava cools so quickly that atoms cannot organize into mineral crystals.

Question 4

A mineral splits repeatedly along flat planes when it shows which property?

Cleavage follows weak planes in a crystal structure; fracture breaks in other patterns, such as quartz's curved surfaces.

Question 5

What does a typical geode hide beneath its plain outer shell?

Mineral-rich water deposits crystals on a geode's inner walls, often leaving an open center.

Question 6

Which fragment shape marks conglomerate rather than breccia?

Water and waves round clasts during transport, while breccia keeps noticeably angular pieces.

Question 7

What do geologists call parallel layers caused by aligned minerals in metamorphic rocks?

Pressure rotates platy or elongated minerals into alignment, producing sheet-like or striped foliation.

Question 8

Why does granite usually contain crystals large enough to see?

Slow cooling gives quartz, feldspar, and other granite minerals time to grow into visible crystals.

Question 9

Which fine-grained sedimentary rock readily splits into thin flakes?

Geologists call this splitting tendency fissility, a hallmark of finely laminated shale.

Question 10

Which mineral can make up nearly all of a limestone rock?

Limestone can be a monomineralic rock, showing that a rock may contain just one mineral type.