Name on Rice - What''s that liquid?

[somehowcollide]

Hi everyone, I have a question that''s been boggling my mind. I figured if anyone knew the answer it would be here, among the wealth of knowledge and experts found on Pricescope!

I am curious to find out the liquid that is used in pendants that display writing on small grains of rice. This oil magnifies the print on the oil, and allows to rice grain to float within the vial. It seems quite viscous and is probably some sort of oil.

Anyone know what this liquid is? I am attaching a picture for your reference. Thank you friends