The Aggregate Vermiculite Grade A-3 is widely used as a component of growing media for professional growers and as a cover for seed topping. Vermiculite is the geological name given to a group of hydrated, laminar minerals which are aluminum-iron-magnesium silicates, resembling mica in appearance. When exposed to intense heat, the material expands or exfoliates.
- pH 6-9 (in water)
- Moisture loss at 230°F: 4-10%
- Sintering Temperature: 2100-2280°
- Boiling/Melting Point: >1000°C
- Meets ASTM C516 Type 1, Grade 2 specifications