THIS!
You have to know what to buy if you want to buy as an investment piece.
Edit: Was thinking and came to the following conclusion:
1.) The nowadyas calles "investment pieces" such as VcA are not worth the money they ask for. Assumed that VcA will go down or something happens, that makes wearing them indiscussable you'll get the price for the materials , best case. What would that be?
2.) Every - and I mean literally EVERY stone - looses its value dramatically once set in a ring / bracelet etc.
3.) For the normal customer it is extremely hard to see if the stone was treated in any way, a thing that will lead to value-loss obove your nightmares. A gemnoligist can tell you, but this is something you have to pay for.
4.) Gold is not that as stable as it was before. Most of the economypersons assume, that the hausse might be over soon. Same to silver, so loss in value again.
5.) Additionally to that, every stone has its own characteristics, that you have to know to decide which one to take. I won't understand that cut-fixation going on on diamonds for example- it is simply 1 C out of 4 from which at least 3 count more that "cut" (see above) - if you want me to give you a hint: always go for clarity and color befor carat and this before cut. Why? IF diamonds become rarer and rarer, combined with color d / e / or perhaps f simply impossible to find.
6.) If you want to buy jewelry, buy something you really really really love. You won't get the money back you invested, except you are totally into stones and know exactly what to buy, where and when or you are totally lucky (see-> Morganit!). Few years ago I bought a few (loose) Alexandrites. In those days, the stone was totally unknown and I got them for a penny. Today, their value tripled, but: a) I had time, b) I was super patient c) I knew what do lookg for and d) I had a gemnologist I could trust as his family was working with my grand-grandparents already. e) last bur not least: those beauties lie in the bank, sometimes I would visit them but that's it.
So, as an investment piece- go for the one you love (in this case handbags)