The volcanic mineral vermiculite has many uses, ranging from gardening to construction. Its closest relative is perlite, a great soil conditioner. Not only does vermiculite loosen up soil and retain moisture, but it is also an ideal fireproofing material, to name a few uses. Vermiculite can be expensive to purchase in large amounts, but many gardeners and builders find that not many other products compare to its benefits.
Gardeners don't often have the luxury of always having perfect soil for their crops or flowers. To make the soil more suitable, vermiculite can be amended into the plot to make the soil retain moisture more effectively, promote quick start-up growth, assist in aeration to provide more air circulation, and make the soil more nutrient-rich. Vermiculite can be worked into natural soil along with compost or peat.
Vermiculite is used in construction for the vinyl liner on swimming pools. Workers usually layer a mix of vermiculite and cement over the pool walls to create a smooth pool bottom that won't feel uncomfortable to bare feet.
Plant seeds can be started in vermiculite without any other soil. Many greenhouse and indoor gardeners use vermiculite to start cuttings, seedlings or seeds. This is because it is already sterilized and the gardener doesn't have to worry about root rot. It acts as a sponge, holding excellent moisture and upping a seedling's chances of surviving and thriving to be a strong mature plant.
Insulation and Fireproofing Materials
Vermiculite has a natural ability to expand, shrink, swell and to be fire retardant, making it beneficial to be used as an insulator in concrete and plaster mixes. It is often used as a "cementitious spray-on fireproofing."