The model shown on sketchfab.com is not shown properly.
The reason is the material shader created with Blender 3D version 2.8 and the export tool for this application.
Let's see these steps:
- create a circle into a vertical plane;
- use edit area and proportional editing to create the shape of the pear;
- cut this shape on half;
- use the screw modifier to create the model of the pear;
- for colors and texture, you can use the web or use shaders;
- I used shaders with noise and color ramp all mixed with mixed shader;
If you want to see my work then the original blend file can be found here.