Mercury:

* Dominant Surface: Rock, primarily silicate minerals (like feldspar and pyroxene) and iron.

* Key Features: Heavily cratered surface, indicating a long history of impacts. Large iron core.

Venus:

* Dominant Surface: Rock, dominated by volcanic basalt and some granite.

* Key Features: Extremely dense atmosphere of mostly carbon dioxide, leading to a runaway greenhouse effect. High surface temperatures (around 900 degrees Fahrenheit). Active volcanoes.

Earth:

* Dominant Surface: Rock, with diverse surface features including continents, oceans, mountains, and valleys.

* Key Features: The only planet known to harbor life. Abundant liquid water, a dynamic atmosphere, and plate tectonics.

Mars:

* Dominant Surface: Rock, predominantly composed of iron oxides (which give Mars its distinctive red color), basalt, and other minerals.

* Key Features: Thin atmosphere of carbon dioxide. Extensive evidence of past liquid water, suggesting a once warmer and wetter climate. Vast canyons, volcanoes, and polar ice caps.

In summary:

The inner planets all have rocky surfaces, but their composition and surface features vary significantly due to their individual geological histories, atmospheres, and proximity to the Sun.