Tingo Tanca, a wholesale company dealing primarily with gemstones, was founded in 1980. Physically based in Denmark, it was among the very first in the business to have established a full-scale Internet activity. By 1998, the complete range of its products had been made available on the web.

In more than one respect, this undertaking—at the time a definite jump into the unknown—put stronger demands on the company's standards of accuracy. Pictures, sizes, shapes, descriptions, names, to mention only these, had to be as nitpickingly truthful as possible—by no means an frivolous task. In particular the company felt that it had a responsibility to adhere to what the single gemstones actually were, mineralogically speaking, or at least to a consensus agreed upon by professionals, as opposed to what the fancies of self-styled gurus wanted them to be for more or less avowable purposes.

In the course of time, Flat Stones made of a wide variety of gemstones—which, ironically, had originally made their way into the catalogue for no other reason than a shipping mistake committed by a manufacturer—were to become synonymous with the company's aim for quality. By late 2007, when the company's owners thought of a more pleasurable way of spending their existence, they had become true collector's items, sold worldwide.

The links below are to the original pictures posted on Tingo Tanca's website, rendered with varying degrees of aesthetic success, as both the equipment used and image manipulation techniques were upgraded throughout the years. They are approximately listed in alphabetical order, the mineral's name appearing in bold. It should be kept in mind that trade names are occasionally better known than any kind of mineralogical designation, so the best way to find a specific stone is to use the browser's search function (with the correct spelling, obviously).

All pictures are in jpeg format and may be downloaded and used freely, under the following conditions (specified in the files' IPTC tags and Comments):

• The gemstone name associated with this file may not be changed or otherwise altered.
• The IPTC and Comments tag may not be deleted, changed or otherwise altered.
  
• These files may not be uploaded to, nor used by, any of the websites connected with the Wikimedia Foundation (broadly speaking known as "Wikipedia")