three.js/examples/materialx/open_pbr_surface_pearl.mtlx

<?xml version="1.0"?>
<materialx version="1.39" colorspace="lin_rec709">
  <surfacematerial name="Pearl" type="material">
    <input name="surfaceshader" type="surfaceshader" nodename="open_pbr_surface_surfaceshader" />
  </surfacematerial>
  <open_pbr_surface name="open_pbr_surface_surfaceshader" type="surfaceshader">
    <input name="base_color" type="color3" value="0.8, 0.75, 0.7" />
    <input name="specular_roughness" type="float" value="0.35" />
    <input name="specular_ior" type="float" value="1.5" />
    <input name="subsurface_weight" type="float" value="1.0" />
    <input name="subsurface_color" type="color3" value="0.8, 0.75, 0.7" />
    <input name="subsurface_radius_scale" type="color3" value="0.3, 0.5, 0.3" />
    <input name="coat_weight" type="float" value="1" />
    <input name="coat_roughness" type="float" value="0.15" />
    <input name="coat_ior" type="float" value="1.68" />
    <input name="thin_film_weight" type="float" value="1.0" />
    <input name="thin_film_thickness" type="float" value="0.420" />
    <input name="thin_film_ior" type="float" value="2" />
  </open_pbr_surface>
</materialx>