perlite

Perlite is used almost exclusively in technical horticultural and construction contexts. It is characterized by its stark white color and lightweight, popcorn-like appearance, which distinguishes it from other soil amendments like vermiculite. In gardening, it is valued for its ability to create air pockets and prevent soil compaction, making it a staple for succulents and seed-starting mixes.

As a material substance, perlite is treated as an uncountable mass noun. It refers to the mineral substance in bulk rather than individual grains. Consequently, it does not have a standard plural form in professional or technical usage.