2. The bonds of Si-o-Si is not beeline but zigzag Ine The angle of oxygen point is 1450 in silicate 3. For every oxygen, there is at most two SIO4 tetrahedrons can share it 4. The sio tetrahedrons can exist isolated or connect each other at common point2. The bonds of Si-O-Si is not beeline but zigzag line. The angle of oxygen point is 145º in silicate. 3. For every oxygen, there is at most two SiO4 tetrahedrons can share it. 4. The SiO4 tetrahedrons can exist isolated or connect each other at common point