Diabase!

This rock appears to be basalt or possibly diabase. Here are the characteristics that lead to this identification:

Texture: Both basalt and diabase are typically fine-grained with small, visible crystals or mineral grains. Basalt cools quickly, leading to a fine-grained texture, while diabase has a mix of fine and coarse grains due to slower cooling.

Color: Basalt is usually dark gray to black, and diabase can be similar in color. The rock in this image has a greenish color with lighter speckles, which fits both descriptions.

Surface Features: The small spots or chips might be iron oxide (rust) or other mineral inclusions, which can sometimes be seen in weathered basalt or diabase.

Formation: Basalt forms from the rapid cooling of basaltic lava exposed at or near the surface of a planet or moon. Diabase, also known as dolerite, forms from magma that cools slowly underground but faster than granite, leading to a mix of grain sizes.

Usage: Both rocks are used in construction, for road base material, as well as in the production of rock wool, insulation, and as an aggregate in concrete.