Even I'm trying tor replicate that smoothness.
Here's a tip VishaD shared on a thread-
Flatten all your layers into one layer after you are done blending
Duplicate the layer
Click on filters>smart sharpen. Set it to 500% and radius 0.3.
Then click on filters again and go to stylize>diffuse and select ansiotropic.
Once you do that dial down the opacity of the duplicated layer to 60% and the fill to 30% to get a topaz like effect.