How to make dark background professional catalog photographs ?

When my mother has done this, she's used http://www.flickr.com/photos/calliope/46822251/in/set-1636821 with good lighting. This will work for smaller items, it's more complicated with larger ones.

Yep, http://planetphotoshop.com/photo-reflection-effect.html (Google "reflection in photoshop" for tons of tutorials.)

It's done in Photoshop or any other image editing software - GIMP, for example, which is free.

Could that be photoshop? It isn't making sense to me that the "reflection" would appear that way (straight down, not angled the way a floor would be) Real reflections don't angle with the floor, dude. It's possible to do it in Photoshop. It's also possible to do it with some black velvet and a pane of glass.

If you want to do this in a photograph (and not resort to photoshop) you need a flat black http://lightbox%20for%20photographing%20jewelry with a reflective (or semi-reflective) floor.

At the auction house where I worked, this is how we often photographed the jewellery. We used a glass plate. That way I could use snot tape or hot glue to hold items in place if I was photographing a group, and if I had a small decorative object that needed a certain angle or an item that needed to be displayed upright, I could re-adjust it several times if needed after looking at the shots without ruining a paper backdrop. http://kaypickens.com/food-photography-on-black/ talks about using a plexi plate under food photography. You'll see that the reflections are the same.

This is often done with a http://www.estreetplastics.com/Black_Plexiglass_Sheets_s/75.htm. Alternatively, a sheet of regular glass or http://www.estreetplastics.com/Frosted_Plexiglass_s/142.htm (for a softer reflection) is placed over an opaque flat black surface. The item to be photographed is placed top of the reflective sheet inside of a flat black lightbox (on preview, I see this has been mentioned already). You can http://www.amazon.com/exec/obidos/ASIN/B005SSMT8A/metafilter-20/ref=nosim/ intended specifically for this kind of product photography (although the item I linked doesn't have very good reviews).

Very probably this was done with a black roll of backdrop paper that is hung up behind and above the table, and rolled down and over the top of the table. A sheet of glass is placed on top of the paper on the table for the reflection. As you can see in your example, lighting is very restricted.

Yup, as RichardP said, acrylic or plexi is the way to go. You can spend your photoshop time cloning out the scratches and dust but the reflection will look like a million bucks! You can probably get some at your local glass shop.