Dester1, you can wear a jade bangle with a watch or the love bracelet. Technically, jadeite is harder, so if anything were to scratch, it would be the metal, but in a minor way. One could buff that out after a few years on a jeweler's wheel in a minute.
Jadeite is most vulnerable to cracking or chipping with hard, sudden impact force, such as being dropped to a hard floor, or smashed against something with force. Though it is pretty hard, it can be brittle, and therefore is not as tough. The crystals are like interlocking tiles, and this explains some of the patchiness in all jadeite except for those with invisible, microcrystalline structure.
Nephrite is slightly less hard then jadeite, but much tougher, and will survive impact hits better. This is because the crystals are long and hair like. Think of the flexibility of a suspension bridge, and you get the idea. The long crystals can carry out a shock wave better then jadeite. The crystal structure in nephrite creates an even, creaminess and uniformity.
If you want to try stacking, I say just try it and see if you feel that it's something that you take to. Hope this helpful! A lot depends on how you treat your jewelry, as some are tougher on things then others.
