A configurator I can't say but in design software there is Rhino3D (RhinoGold) which is very good for jewelry.
http://www.rhino3d.com/fr/
http://www.rhinogold.fr/
As for inter-software compatibility, it gets complicated...
You will still be able to export or import a CAD file between software but with some losses.
That is to say that if you take a file (jewel) from another software you will have difficulty reworking it, especially with complex pieces such as jewelry!
I have a friend in jewelry, who uses Solidworks for his designs. The good thing is that you can play with several modules that interest you with ease.
Then, as Tomalam says, Rhino has a good jewelry module called Gold which offers quite simple things.
As far as compatibility between software is concerned, there are always gateways that allow you to work on several software. (Export in special formats, plugins, or third-party software)
I don't really understand what you mean by configurator, but if you're looking for a software you want to create a library of configurable rings or other, it's quite possible with this kind of software.
It also depends on your degree of investment, and your budget.
By configurator, I mean an application capable of using elements of jewelry to compose another - Example: I have made one or more ring heads and several ring bodies (ring) and I would like to assemble any head on any ring in "one click" (at least very easily). The same goes for other elements.
Rhino and Solidworks (and variations) seem to be very relevant for jewelry design, but they are not free.
Blender is free. Is it also a relevant choice for jewelry?
Blender is very efficient but doesn't work at all like SW.
He is a modeler, more in the Rhino spirit.
To sum up, we only build in surface but it also doesn't have the same use as SW, and it's not a hindrance for a job like yours which doesn't require the same things as a mecha designer.
I followed the tutorial that Tomalan posted when I started and it's really very well done.
So nothing prevents you from training (some chapters can be "skimmed") and seeing if it corresponds to what you are looking for.
But I repeat, it's an excellent software, open source at that.
A priori, Blender would not be parametric and therefore would not allow to automatically adapt the proportions of a piece of jewelry following the modification of a dimension such as the size of the finger for a ring; Is that right?
I was told this weekend about 2 applications: Netfabb and Minimagics, which seem to allow you to easily assemble STL files and play, a priori, this role of configurator.
But, do you know if they allow you to do this, including by adjusting dimensions (finger size for a ring, ...) - always in the same idea as that of a configurator? And are there any constraints to these assemblies?