A LED mini nightlight that changes colour is used to illuminate the crystal light by fitting inside the printed model.
The mini nightlight was obtained from a large on-line shopping website, quite cheap.

UPDATE includes a  modification to allow more light at the top of the crystal model.

Print instructions

I printed the transparent PLA crystal model with a 0.6 mm shell thickness and a 10% concentric fill.
The concentric fill acted like a support for some of the crystal print due to the variations in height around the model.

I printed a Prusa Galaxy Black PLA base, the mini nightlight fits in the centre of the base.
The crystal model has a hole in the bottom that replicates the mini nightlight and thus fits over the mini nightlight keeping all the model central.

Some experimentation may be done to get better illumination.
When printing at 100% the light source hole at the bottom of the crystal print is 39 mm in diameter, 22 mm tall with a dome on top. Depending on your light source you can print a couple of layers, measure the diameter and scale accordingly using Prusa Slicer.

UPDATE 30/12/2022

Following a comment made by a maker regarding the top of the crystal light. They stated not enough light shines through the very top of the model. Therefore I have modified the model in a 3MF file and added it to the files section.

It was an easy modification, using PRUSA slicers own feature. I added a ‘Negative Volume Cylinder’ through the centre of my model. Using the 3MF file included you can see the modification and alter it if you so wish.

Just a note, as yet I have not printed  the modification myself (another project demands my attention) . If you do find any problems please let me know.