Unity thinks my Quaternion is a Float

Hello,

I am trying to set the rotation of an emitted particle from a ParticleSystem to the direction it is travelling in.

This is my code:

 void RotateParticles()
 {
     ParticleSystem.Particle[] x = new ParticleSystem.Particle[gameObject.particleSystem.particleCount+1]; 
     int y = particleSystem.GetParticles(x);

     for(int i = 0; i < y; i++)
     {
         Vector3 offset = gameObject.transform.position - x[i].position;

         if(offset != gameObject.transform.position)
         {
             Quaternion rotationPoint = new Quaternion();

             rotationPoint.SetLookRotation((offset), Vector3.up);

             x[i].rotation = rotationPoint;

         }
         else
             Debug.Log("False");
     }

     gameObject.particleSystem.SetParticles(x, y);
 }

The error thrown is 'cannot convert type UnityEngine.Quaternion to float' however, as far as I can tell, both the particle.rotation and rotationalPoint variables are in fact quaternions.

Either I'm totally wrong and the Quaternion variable I have just created isn't a Quaternion at all (assuming Unity throws its errors respectively) OR they are both quaternions and this error is false OR the rotation of a particle is not a Quaternion (assuming Unity doesn't throw its errors respectively).

I'm lost!

Any and all help appreciated.