I think JEG has a proper Lightbox. I just take lots of photos in different parts of my house at different times of day. The one great thing about phone cameras, is that I can see the results immediately and retake the picture if needed.
Currently in Florida, I'm taking my photos mid morning in my all white, east facing bathroom. It has lots of windows which are covered with white sheer curtains. I put a white towel on the white floor next to the tub, which has white tile on the side. I drape a white towel over my knees to reflect more white light back onto the pearls laying on the towel. If I put the floor towel next to the tub, the pearls are in slight shadow. If I move the floor towel more towards the center of the bathroom, they are in brighter light coming from the window over the tub. I take photos in both positions because the small change in shadow vs. direct lighting makes a huge difference in how the pearls look.
Then I upload the photos to my Mac laptop and play with the Photos application. I crop the photos to make the pearls bigger. I change the color saturation and light brightness so the photo mimics what my eye saw when I took the photo. Because the background is white and the pearls are light, the camera wants to make everything grey, so I do have to up the brightness to make the white towel look white. Also, I find when I post photos in Pearl-Guide, they lose some color, so I up the color saturation just a bit in Photos so that when I post the photos here, the pearls look like they look to my eye. It's still not perfect. Sometimes I just cannot capture the pearl luster and color that my eye sees.
When wearing pearls, I try to take the photos in natural light, but in the shade. So either in the bathroom, or on my south facing covered back porch.