Common glass is made from clean sand, soda, and limestone. Various other elements may be added to modify the properties of the glass - colour, density etc.
a transparent material
a
A transparent stone can be made of any material. If you suspect that it is a diamond, the field test for diamond is extreme hardness.
It is refracted or 'bent' at the surface of the transparent material. (Obviously, to be directed at a transparent material the light must be travelling through a material that is at least partially transparent.) Please see the link.
The transparent teeth-straightening ceramic braces are originally made as spacecraft material. The transparent ceramic is called Translucent Polycrystalline Alumina (TPA) developed by Ceradyne .
Sand would not unless some particles are made of biotic, organic material.
Transparent
so a blind person on the other side can be seen.
Yes, cling film is a transparent material.
shadow formed on the other side of transparent material
If it is perfectly transparent, nothing. It can refract and reflect the light. For example, a lens is made of glass which is transparent. The important properties are the refractive index of the material and the angle that light hits the object at.
Water