Some toys say silicone, but they aren't all silicone. Thus its good to be cautious storing silicone toys together since if they aren't entirely silicone they'll try to bond to each other (causing an icky, tacky texture and "melting" effect.) If a toy is made of 100% silicone they can touch other toys of that sort. If not, they can be kept separate by keeping them in a plastic baggies as Rossie says.

Brands like LELO, Tantus, and Fun Factory tend to have trustworthy 100% silicone products (As well as Evolved silicone vibrator enhancers). Vixskin is good silicone too, but I recall reading that vixskin silicone doesn't play well with others. Something about the soft type material. I forget all the details of that though.

Silicone lubes should generally be avoided for silicone toys though. Lubricated condoms should also avoid being used on silicone toys as they might have silicone lube in the ingredients. Certain silicone lubes are fine I hear, but I think it's easier to just use water based. less