2 Minerals and Their Properties Free Online FlashCards

What defines a mineral?

A mineral is a naturally occurring, inorganic solid with an orderly internal crystal structure and a characteristic chemical composition.

How does a rock differ from a mineral?

A rock is a naturally formed material made of one or more minerals or other solid material.

What gives each mineral its characteristic properties?

A mineral’s atoms and chemical bonds give it characteristic properties.

What are the compositions of quartz, halite, and calcite?

Quartz is silicon dioxide (SiO₂), halite is sodium chloride (NaCl), and calcite is calcium carbonate (CaCO₃).

What characterizes silicate minerals?

Silicate minerals contain silicon and oxygen and are especially abundant in Earth’s crust. Feldspar and quartz are common examples.

Why is color alone unreliable for identifying a mineral?

Geologists use several properties together because color can be changed by impurities, and different minerals can look alike.

How do cleavage and fracture differ?

Cleavage is splitting along smooth, repeated planes of weakness; fracture is breaking without cleavage, often into irregular or curved surfaces.

What determines whether a mineral’s crystal form is visible?

Crystal form is the external shape a crystal develops when it has room to grow. Crowded crystals in rocks may not show their full shapes.

How does cooling rate affect crystal size?

Slow cooling underground often produces larger crystals, while rapid cooling at the surface usually produces smaller crystals.

How can existing rocks produce new minerals?

During metamorphism, heat, pressure, or chemically active fluids can cause minerals to recrystallize or react into new minerals. Weathering can also produce new minerals, such as clay, from older ones.

What does luster describe?

Luster describes how a mineral’s surface reflects light; examples include metallic, glassy, pearly, and dull.

What is a mineral’s streak?

Streak is the color of a mineral’s powder, revealed by rubbing it on an unglazed porcelain plate. It can differ from the mineral’s outward color.