Both perlite and vermiculite are open mined in various countries. Perlite is what's known as volcanic 'glass', whereas vermiculite is actually a mica like mineral. Perlite is also put through a heating process to persuade it to 'pop' in order for it to be useful in potting soil as well as other applications. Both materials have a number of other uses, notably in the construction industry; this link has a separate embedded link to information on vermiculite too https://sciencing.com/perlite-5402928.html.

Ultimately, it depends precisely what you mean by sustainable; both products are mined all the time for other uses, but the heating process for perlite could be considered non environmentally friendly. In terms of horticultural use, there is a more environmentally damaging substance (when dug up) contained in many potting soils, which is peat, of which there is obviously also a finite supply. This https://www.greenschoolsalliance.org/blogs/16/428 gives a little more information on ingredients used in potting soils and their environmental sustainability.

Both perlite and vermiculite are open mined in various countries. Perlite is what's known as volcanic 'glass', whereas vermiculite is actually a mica like mineral. Perlite is also put through a heating process to persuade it to 'pop' in order for it to be useful in potting soil as well as other applications. Both materials have a number of other uses, notably in the construction industry; this link has a separate embedded link to information on vermiculite too: What Is Perlite?.

Ultimately, it depends precisely what you mean by sustainable; both products are mined all the time for other uses, but the heating process for perlite could be considered non environmentally friendly. In terms of horticultural use, there is a more environmentally damaging substance (when dug up) contained in many potting soils, which is peat, of which there is obviously also a finite supply. This For Peat's Sake: Conventional Potting Soil And The Environment gives a little more information on ingredients used in potting soils and their environmental sustainability.

Both perlite and vermiculite are open mined in various countries. Perlite is what's known as volcanic 'glass', whereas vermiculite is actually a mica like mineral. Perlite is also put through a heating process to persuade it to 'pop' in order for it to be useful in potting soil as well as other applications. Both materials have a number of other uses, notably in the construction industry; this link has a separate embedded link to information on vermiculite too https://sciencing.com/perlite-5402928.html.

Ultimately, it depends precisely what you mean by sustainable; both products are mined all the time for other uses, but the heating process for perlite could be considered non environmentally friendly. In terms of horticultural use, there is a more environmentally damaging substance contained in many potting soils, which is peat, of which there is obviously also a finite supply. This https://www.greenschoolsalliance.org/blogs/16/428 gives a little more information on ingredients used in potting soils and their environmental sustainability.

Both perlite and vermiculite are open mined in various countries. Perlite is what's known as volcanic 'glass', whereas vermiculite is actually a mica like mineral. Perlite is also put through a heating process to persuade it to 'pop' in order for it to be useful in potting soil as well as other applications. Both materials have a number of other uses, notably in the construction industry; this link has a separate embedded link to information on vermiculite too https://sciencing.com/perlite-5402928.html.

Ultimately, it depends precisely what you mean by sustainable; both products are mined all the time for other uses, but the heating process for perlite could be considered non environmentally friendly. In terms of horticultural use, there is a more environmentally damaging substance (when dug up) contained in many potting soils, which is peat, of which there is obviously also a finite supply. This https://www.greenschoolsalliance.org/blogs/16/428 gives a little more information on ingredients used in potting soils and their environmental sustainability.