What are some examples of opaque objects?

The majority of objects are opaque, which means you can't see through them. This is due to the fact that light can't pass through them. Examples of opaque objects include wood, gold, cement, metal, some types of colored plastic, vegetation and so on.

When light strikes an opaque object it is either absorbed by the object or it is bounced off or reflected by the object. For example, white objects reflect light, which is why they are cooler to the touch. Dark objects absorb light and transform it into heat. Other objects absorb some wavelengths of light while deflecting others.