Can you see the crystals in basalt?

In some cases, yes. Some types of basalt have large enough crystals that they can be seen with the naked eye. These crystals are usually of the minerals plagioclase, pyroxene, and olivine. In other cases, the crystals in basalt are too small to be seen with the naked eye and can only be seen with a microscope. These crystals are usually of the minerals magnetite, ilmenite, and apatite.