Fumed Silica

Gasil 23 is a fine, white, free-flowing micronised silica gel with an average particle size of less than 3 microns. It is generally used in concentrations of 10 to 100% to thicken resins.
Gasil 23 is colourless so when used with Hxtal or Araldite 2020 is suitable for making translucent or tinted fillers.
This is a VERY lightweight powder, 15g is equal to around 250ml of water in volume.