I think if you have gold jewelery, I would not sell it but hold on to it.
The next thing you should invest in are some sustainable and return on investment things like energy and heat sources that is best for your area. If solar panels work in your area then research them and invest in those and a good battery bank.
Once you have food, heat, power, and housing taken care of, then good training in skills that would be valuable post SHTF is the next area of an excellent investment. Manuals, videos, books, etc.
Finally, if you are looking at a moderate collapse (which I think is very Pollyanna knowing how unstable the entire world economy is based on a host of fiat currencies and an uneducated populace) and you just want to stick your money in a safe investment, I honestly think of the money you plan to invest you should be mildly diverse: 15% gold, 50% silver, and research some other things like reading through and listening to intelligent gurus like Jim Puplava from Financial Sense News Hour and his side kick. He is pretty balanced, both politically, deflation/ inflation position, and PMs vs other commodities.
These decisions really are more fine tuned to where you live, your situation (how much you have to invest and can afford to lose), how well you are set up to survive most scenarios forecasted, and what you have to sell as far as knowledge and skills if you find you made some bad bets and lost a majority of your investments.
I'm sorry I am not more helpful but it really does vary significantly based on each person's situation.