A layer of a transparent material rests on a block of fused quartz, whose index of refraction is $1.460 .$ A ray of light passes through the unknown material at an angle of $\varphi_{1}=63.65^{\circ}$ relative to the boundary between the materials and is refracted at an angle of $\varphi_{2}=70.26^{\circ}$ relative to the boundary. What is the index of refraction of the unknown material?