Every mining area of importance is known and exploited by the Germans; they have their representatives and buyers of rough stones in every country, and from long experience they are able to buy and ship the material at the lowest rates. Normally, much is brought to Idar-Oberstein in the first instance, where it may be inspected and then bought by auction on specified dates. Merchants buy the rough stones according to their requirements and separate markets, for after being fashioned, the cut stones are again exported to every country in the world.

The district is actually well situated for this industry, which has such widely international interests. It is readily accessible by rail from every country on the Continent, yet it lies in a beautiful region of mountains, rivers, valleys and forests, away from the diversions of any large town. The river Nahe which winds through the valleys has been of considerable importance in building up the industry, as has also the neighboring mountains. For very many years, the Nahe supplied water power for the large wheels used in slitting and grinding the agates, while the rough agate itself was found close by and worked until the deposits were exhausted. The hills also supplied some of the stone wheels which were used, hard sandstone laps of great size and most suitable for the working of agates and other types of quartz. Water power is still used to some extent, but most mills have now turned to electrical power, which is supplied cheaply by the grid system. Also the great sandstone wheels have now been mostly replaced by vitrified grinding wheels, carborundum being used as the abrasive for all stones with a hardness below 8.

On the Continent, tripoli powder is more generally used for polishing stones. Spinel is best polished by a mixture of magnesia and rotten stone. Another widely used material is putty powder, which is a dioxide of tin from the crude oxide, formed on the surface of melted tin. Pumice stone is another material much in use. Almost each stone varies, and experience is the chief guide to the lapidary. For instance, spinel is softer than corundum, but it is not so easy to work. Ruby is tougher than sapphire, and alexandrite is more difficult to work than sapphire despite its lower hardness. Zircons vary; the greens are cut with rotten stone or on a wet wheel alone, and polishing is done with a slowly rotating wheel.

Various grades of emery, known by numbers, may be obtained, the range varying from 6 to 600. The number represents the number of holes per inch in the grading sieve through which the powder has been passed. The powders are applied in the form of a paste to the metal wheels, and these vary in composition according to the material being fashioned. Pewter, copper, and leaden wheels are all used, and in these, the grains of emery are embedded by revolving the laps at speed. Almost continuous cooling by water is necessary to avoid over-heating, and this process is sometimes known as mud-lapping.

The number of lapidaries employed in the war years 1939 to 1945 is a matter of conjecture. It was estimated that about 5,500 cutters were employed in the diamond industry in the year 1941, outside Germany and the countries it controlled in that year. Of the many thousands formerly employed in Belgium and Holland, only a few hundred were working in their old factories during these’ years. The Germans controlled production through a Diamond Control Office, and there was little reward or scope for the individual under Nazi methods.

In Brazil, gem cutting is now a fast growing and prosperous industry, and though entirely new to this country, expansion and development point to the fact that the industry is likely to remain there. It must be remembered that many varieties of gem stones, in addition to diamond, are found in this vast country, and old connections exist between Brazilian stone dealers and those who were formerly stone merchants in Germany. Cutters in Brazil number about 5,000, with many more apprentices, but this number includes those cutting semi-precious stones. Previous to 1939, most of the rough material was exported, but this is now being cut locally, in addition to material imported from London. The 1943 estimated production was 275,000 carats, of which 15,000 carats were carbonado (not gem quality diamond). Cutting centers are established in Rio de Janeiro, Bello Horizonte, and Theo-philo Ottoni.

In 1940, some 18 factories were again being worked, and about 52,000 carats of cut stones, valued at one and a half million pounds, were produced. The next year, 408 workers were employed, and by 1945, there were 45 cutting factories in the Union. In 1950, there were 57 establishments, with 572 registered employees and 174 apprentices, the value of diamonds cut in that year being nearly twenty-three million dollars  (£7,935,511)-

As we have already noted, the German occupation of the Low Countries in 1940 resulted in the scattering of a great number of skilled craftsmen to whichever country would accept them. This resulted in the establishment of a diamond cutting industry in many fresh countries, such as Canada, Israel, South America (particularly Brazil), Cuba, New Zealand, and even Borneo and the Dutch East Indies, although the Japanese War in 1942 necessitated a second migration for those unfortunate enough to settle in the last two areas.
Stones cut in Canada (Toronto is the chief center) are of a high standard. Here, the industry was commenced in 1940. The grades of work are highly specialized, and the stages of cutting are divided among a greater number of workers in order to obtain superior results. Many apprentices are working under the guidance of former Belgian and Dutch craftsmen, and in 1944 some 70 apprentices were being employed at a high rate of pay.