This category of subterranea is a little strange, as there is no good word for this kind of caverns. So as we do not have a name, the heading is rather descriptive, and not really the term to name this kind of caverns. The term rock mine is already defined (see above) but it does not exactly represent, what we mean. So we try to explain which kind of subterranea is meant.
Mines are normally producing valuable precious or semi-precious minerals, ores or coal. Limestone, marble, granite and other rocks are in general quarried, which means an open cast mine. It is really uncommon to mine these rocks underground, as underground mining is difficult and expensive. Normally those rock are not valuable enough to mine them underground and still make profit.
Under certain circumstances, in areas which do not allow open cast quarrying, rather worthless limestone or sandstone is mined underground. Most of the underground quarries are historical, as transport then also used to be complex and expensive. As a result it was cheaper to extract the rocks locally in an expensive way than to transport them over long distances. This changed with railroads, modern roads and lorries. Nowadays, stones are traded on the world market and often come from low-wage countries. Exceptions are stones of exceptional quality or reputation, such as Carrara marble. The people working in these underground quarries were called stone-hewers, stone cutters or quarrymen, not miners. The rocks that most often led to underground mining are:
showcaves.com deals with underground sights, quarries are usually not included. Underground quarries are a different story, some of them have huge underground cavities. The mine itself is quite unspectacular, just huge chambers, but those huge spaces were used for something completely different afterwards, which makes them interesting. And as a result we see such rock mines as subterranea, not as mines, as the reason for listing them is generally the later use.
Underground quarries, although much rarer than mines or surface quarries, are nevertheless very numerous. Exceptionally many of them are in fact tourist attractions, but usually not as underground quarries. The special thing about quarried stones is their low value, which usually means that large quantities are mined. This creates huge cavities, often many hundreds of metres long and wide, with a multitude of pillars supporting the ceiling. These huge voids often undergo alternative uses. Here are a few common after-uses.
Many of these uses have their own category in Subterranea. Not all were originally an underground quarry. But in this form of after-use we always give both categories, the underground quarry and the after-use. It is obvious that the quarrying created the cavities and the after-use usually modifies them rather slightly.
The term Rock Mine is easy to understand, so we use it throughout showcaves.com. We listed them under subterranea, as it is not really a mine. And those objects are often called caves, which is completely wrong because caves are natural voids. Of course, we cannot change the names of sites, but we nevertheless list them as subterranea, even if they are named cave.