What is Vermiculite? Vermiculite has been used in various industries for over 100 years and its occurrence as a natural mineral (hydrated phlogopite mica) dates back as far as 3.0 billion years old and it is one of the worlds’ most unique minerals. Some of the largest commercial mines in the world who are exclusive Vermiculite suppliers, are located in Southern Africa, Australia, China, Brazil and USA. Once the ore is mined and graded it is then subjected to a furnacing process which is also known as exfoliation. Exfoliation is a process where the ore is heated to approximately 800⁰C, at this point, water particles in the ore are boiled off and evaporated which then causes rapid expansion to form concertina Vermiculite particles.
Vermiculite is a natural mineral that expands with the application of heat. We use vermiculite that has been exfoliated and this is the shiny material you find in our composts.
Vermiculite has a high cation exchange capacity at 100-150 meq / 100g which gives it the ability to hold nutrients and release them when required. It is a very light weight material and used in growing media, hydroponic systems and also in covering seedlings providing insulation and enough light for the seedlings to germinate. Fertile Fiber uses vermiculite in seed and multipurpose compost.