The material that looks like smoke is actually very tiny particles of volcanic rock, called ash . The ash reached high in the atmosphere, making the Earth cool for a summer, and giving us lovely red sunsets for about a year. Eventually, the ash falls out of the sky, usually with rainfall. Most will rain out near the volcano, but some particles will travel 1000s of miles in the atmosphere. These mainly consist of bits and pieces of broken coral .
Coral is the calcite shell of the coral animal.
Other particles and bits and pieces of broken clams and other calcite-secreting animals and plants. Below, a closer view of a coral reef. Below, an even closer look at the coral from the above photo, showing the many coral animals living communally. Each individual is a polyp . Below, a cartoon showing an individual coral animal.