Here are some pictures of miniatures that were sculpted by a web visitor. (Igor) and my thanks go to him with sharing the pictures and the information about the clay and techniques that he uses.

The clay is something I have never used but it seems pretty interesting. It is called Beolin Plus and here is some information about it from the manufacturers website

BEOLIN PLUS is a polimer moulding mass, whose characteristics exceed all well known materials of this kind, such as clay, modelling clay, etc. Modeled objects can be hardened without changing its shape or dimensions, simply by baking or boiling at 130 degrees. Beolin softens very quickly in your hands and it becomes suitable for modeling. Hardened figures can be further shaped by a chisel, scalpel, file or a sandpaper. Hardened figure can be boiled or baked many times, in case that we want to add more material to it.

Couple of notes about this clay: First off you can boil it to harden it which is a terrific plus and worth giving the clay a try just for this. But secondly you can also continue to work it after it is hardened.

Here is what Igor has to say about working with it:

The material I used is this http://purpurtechnology.com/en/modeling/beolin-plus-b01 . It is, as they say, polimer moulding mass. It is not easy to work with because it is.. kind a stiff. First, you need a lot of time kneading it with your hands. And then, when I get the desired shape(as close as I can get) I`m boiling it, just putting it in boiling water for few minutes. At that point it is rock solid, but it still can be shaped with scalpels, needles and modeling(moduling?) tools. I`m first doing torso, and then just add legs, arms, head.. This moulding mass is very stuborn before boiling and  I haven`t succesed adding wire frame. So, I`m driling little holls and then put a small piesces of wire, to add legs and arms, fists...These figurines are about 100mm high.

Tutorial: How to Cast Miniatures - This is a nice tutorial on how to duplicate miniatures. In the first tutorial I show you exactly how to make a copy of a small and not too complex original like this treasure chest. Casting Miniatures is a lot of fun and not hard at all. How to Cast Miniatures I cast two different treasure chests.

How to Sculpt a miniature treasure chest. A treasure chest is a great first project to learn how to sculpt because it is very easy. You can get a good feel for the modelling putty. In this tutorial I sculpt three different chests and show you some techniques. I also use these chests as part of a Casting Miniatures tutorial. How to Sculpt a Miniature Treasure Chest