siliceous

/sɪˈlɪʃəs/
adjective
  1. Containing or made of silica, especially describing rocks, minerals, or materials.
    • The soil in that region is highly siliceous, which affects what plants can grow.
    • Siliceous rocks like flint were used by early humans to make tools.
    • Some sponges have a siliceous skeleton made of tiny glass-like spikes.
What does "siliceous" mean? | whatsthatwordmean | whatsthatwordmean