Pronunciation: [pjˈuːmɪsɪz] (IPA) 
The word "pumices" is a plural form of "pumice", which refers to a type of volcanic rock. The spelling of "pumices" follows the regular pattern of adding "-es" to the end of the singular form to indicate plurality. The phonetic transcription of "pumices" is /ˈpʌmɪsiːz/. This suggests that the word is pronounced as "PUM-i-siz", with the stress on the first syllable, and the consonant sound of "c" is pronounced as /s/, not /k/.
Pumices are a type of volcanic rock characterized by their lightness and porosity. They are formed when magma containing a high concentration of gas and water is expelled during a volcanic eruption. As the lava cools rapidly, the gases expand, creating numerous fine bubbles throughout the rock. This process results in the distinctive vesicular texture and low density of pumices.
Pumices typically have a pale, whitish color, but they can also exhibit shades of gray, yellow, or even black, depending on the specific minerals contained within the rock. They have a porous and sponge-like appearance due to the presence of numerous interconnected air-filled cavities known as vesicles.
Due to their unique characteristics, pumices have various practical applications. They are commonly used as an abrasive material in cleaning and polishing products, ranging from cleaning stones to exfoliating skin. Pumices are also utilized in horticulture as a soil amendment to improve drainage and aeration. In the construction industry, they are sometimes incorporated into lightweight concrete to reduce its weight and increase insulation properties. Furthermore, pumices have been historically utilized as a natural flotation material, and some historical cultures used them as a building material.
Overall, pumices are a versatile volcanic rock with a low density, porous structure, and diverse applications in various industries.
The word "pumices" comes from the Latin word "pumex", which refers to volcanic rock. The Latin term was likely derived from the Greek word "pymatos", which also means volcanic rock.
