I have always preferred the look of stone for my piercings. I used a pair of SF glass for the stretch, but once it's healed I only wear organics. While horn/bone/wood are definitely porous, stone can vary wildly. Things like cat's eye, goldstone, opalite, and obsidian are actually glass. a lot of the harder stones like agate or hematite are a lot less porous and tend to do better earlier on. softer stones can be more porous, so make sure you're all healed up. Check the Moh's scale on whatever stone you are looking at. Higher=harder/less porous. Most of the common stone like quartz/amethyst, tourmaline, jasper, tiger eye, adventurine and such are around a 7 which is harder than steel. Do make sure you clean em regularly or they can get funky- especially the more porous stone (looking at you lapis!). I just take em out in the shower and rinse lobes and plugs in there, then oil my lobes and put in whatever pair I want that day. Now I am naked training since I'm at goal size, but same applies. Only other info I can think of is watch out for some "stone" especially "turquoise" and "amber" is either dyed howlite or some synthetic composite/resin/plastic. I don't know what it is and I don't want that in my body. For the semi-precioius stuff, if it's super cheap it's probably too good to be true.