About Perlite

Perlite is a glassy raw material which, when heated in a furnace, pops like popcorn and expands by up to 20 times in volume into a white or pale coloured low density material.

Expanded perlite is used in:

  • Various industrial and household applications such as insulation, paint texturing, plaster and concrete fillers, building materials fillers, formed insulation, field conditioners (soil porosity enhancement) and fire proofing.
  • Filter aids (in competition with diatomite).
  • Insulating industrial cryogenic storage vessels.
  • Potting medium in gardening and horticulture to aid water retention and aeration of the soil. 

According to the United States Geological Survey (“USGS”), 560,000 tonnes of raw perlite was mined in the USA in 2018 with most material used internally and some material imported, primarily from Greece. USGS reports show a 12% annual rise in US consumption in 2018 and a 22% rise over 2015. China is the world’s largest producer with most of its production consumed internally.

The market for perlite is well established but in recent years the market for horticultural perlite has been invigorated by the growth in cannabis cultivation following the legalisation of cannabis in various US States and, most recently, in Canada. Only coarse grades of raw perlite from certain sources can be expanded to produce the coarse expanded perlite used as a growing medium for cannabis. Raw perlites from other sources shatter too much on expansion and are not suitable.

It is therefore significant that the Company’s recent commercial trials confirmed that the coarse grades produced from the processed bulk sample produced the expanded product that is of interest to the cannabis industry as well as other more traditional horticultural buyers.

Raw sized perlite typically sells for US$70 per ton at the mine gate but coarse and super-coarse horticultural grades can command a higher price.

Perlite can also have pozzolanic properties and be suitable for use as a natural pozzolan.

The Company is a member of the Perlite Institute. For more information on perlite see: https://www.perlite.org/library/