1. Quartz:

* Appearance: Quartz is typically clear, white, or milky, but can also be pink, purple, yellow, or brown. It comes in various forms, from crystal clusters to smooth, rounded pebbles.

* How to recognize it:

* Hardness: Quartz is very hard (7 on the Mohs Hardness Scale). It will scratch glass.

* Fracture: It has a conchoidal fracture, meaning it breaks in smooth, curved surfaces.

* Luster: It has a glassy luster.

* Cleavage: Quartz does not have perfect cleavage, but may have a slight fracture.

2. Feldspar:

* Appearance: Feldspar is usually white, gray, or pink, and often has a pearly or glassy luster.

* How to recognize it:

* Hardness: It is relatively hard (6 on the Mohs Hardness Scale). It can be scratched by a steel knife, but not by a fingernail.

* Cleavage: Feldspar has two prominent cleavage planes, creating rectangular or blocky shapes.

* Fracture: It may show irregular fractures, but is usually characterized by its cleavage.

3. Calcite:

* Appearance: Calcite can be clear, white, or various colors, and can be found in crystals, stalactites, stalagmites, or as a rock-forming mineral.

* How to recognize it:

* Hardness: Calcite is relatively soft (3 on the Mohs Hardness Scale). It can be scratched by a fingernail.

* Cleavage: Calcite has perfect cleavage, meaning it breaks into smooth, flat, rhombohedral shapes.

* Reaction with Acid: Calcite reacts with dilute hydrochloric acid (HCl), causing it to fizz and release carbon dioxide gas.

Important Note: Always handle minerals with care and avoid licking or tasting them. Some minerals can be toxic. If you're unsure about a mineral, it's best to consult with an expert.