I have heard that the sign of the cross is a sacramental. If true, it seems that this would be something available equally to non-Catholics.
Also, I’m curious whether a rosary is considered a sacramental in and of itself, or if only those rosaries that are blessed are sacramentals.
You know, a few weeks ago, I would have agreed entirely with that. But I’ve since read the Church’s introduction to Sacramentals in the Roman Ritual, and found it enlightening. Here’s the text again:
And why are such simple things like the sacramentals so efficacious in the life of grace? Because their efficacy is dependent on the power of the Church’s impetration, and not solely on the devotion of the subject who uses them. We say that the sacraments work “ex opere operato,” that is, in virtue of the outward signs that are posited. On the other hand, we are accustomed to hear that the sacramentals work “ex opere operantis,” which would mean in virtue of the intensity of devotion in those who use them. Yet this is only part of the truth. The thing is cast in an altogether different light when it is stated in full precision, namely, that the sacramentals work “ex opere operantis Ecclesiae,” which means that their efficacy is in first place dependent on the power of the Church’s intercession, and only secondly on the devout dispositions of the subject concerned.
The emphasis here is pretty clear: the sacramentals work “ex opere operantis Ecclesiae.”
So a sacramental which occurs outside the Church would have less efficacy than one that has as its basis the “work of the Church.” Are sacramentals available to non-Catholics? Of course yes. Can they receive Graces from them? Again, of course yes. But sacramentals which “occur” outside the Church have less efficacy.
…or perhaps we could say “a different emphasis”…
This reminds me of something from the secular world. I recall hearing a discussion about US flags being made in Communist China. One person was outraged at the idea (as was I, at first). But the other person presented the viewpoint that when someone under the communist yoke makes an American flag, that person is reminded of the fact that freedom does exist in the world, and that there is hope. I think we can apply a similar logic to sacramentals. When those outside the Church use sacramentals, they are brought closer to Communion with the Church.
As I see it, the Grace which is imparted to our separated brethren, through their use of sacramentals, is first and foremost the Grace to come closer to the Church.
For the last part, yes a rosary is a sacramental even if it isn’t blessed, although rosaries should be blessed.