1. Color and Texture: This is a good starting point. Observe the rock's overall color, any variations within it, and how it feels to the touch. Is it smooth, rough, coarse, or glassy?

* Example: A smooth, black rock with a glassy sheen could be obsidian.

2. Hardness: Test the rock's hardness by scratching it with common objects of known hardness (like your fingernail, a copper penny, a steel knife). This helps narrow down possibilities.

* Example: If a rock can be scratched by a fingernail, it's relatively soft, like talc.

3. Streak: Scratch the rock across a streak plate (unglazed porcelain) to see the color of its powder. This can be helpful for identifying minerals within the rock.

* Example: Hematite has a reddish-brown streak, even if the rock itself is black.

4. Cleavage and Fracture: How does the rock break? Does it split along flat planes (cleavage) or break irregularly (fracture)?

* Example: Quartz breaks with a conchoidal fracture (curved, shell-like), while halite (rock salt) has perfect cubic cleavage.

Remember: These are just starting points. For a more definitive identification, you'll likely need to use a combination of these techniques and possibly consult field guides or an expert.