Some of the properties are:
1. Gamma, γ-rays are not deflected by electric and magnetic fields. It shows that they do not have any charge.
2. Gamma, γ-rays are electromagnetic waves like X-rays. The wavelength of γ-ray photon is smaller than that of X-rays.
3. The rest mass of a Gamma, γ-ray photon is zero. (Photon has mass zero but it has momentum, why?)
4. Gamma, γ-rays travel with the speed of light.
5. Gamma, γ-rays have very large penetrating power. They can pass through several centimeter of iron and lead.
6. Gamma, γ-rays can produce fluorescene in a substance like willimite.