Monday, 27 July 2009

What's it called?

A problem I encounter relatively frequently is one of common names. More for minerals than fossils, but there are examples of both. I mentioned briefly when writing about chalcopyrite that it is often called peacock ore. It's pretty clear where the name comes from in that case. It's shiny and colourful - so are peacocks. It's not always so obvious.

This morning I had a call from a customer looking for minerals only by their common names - she didn't know the geological names - and I had heard of none of them. A bit of digging found a reasonable answer for one of them and a fairly tenuous answer for another. There are often more than one common name for a mineral, and also the application of the label may also be heavily subjective. Nobody is 'in charge' of assigning the names, anyone can do it and there's no comprehensive database to check up on.

As an example, a great many shapes and variety of quartz crystal have common names attached. I currently have optical, candle, elestial, cactus, fenster, laser and faden quartzes. And this is before colour is considered...

The mineral above is known as lemon (or citrus) chrysoprase. It's not chrysoprase. It's magnesite with nickel in it. So a number of the common names are misleading as well. There are loads (that's an accurate figure - you can quote me) of 'jaspers'. If someone wants to market a stone they've found in commercial quantities, they seem to resort to calling it 'Something Jasper' if they're not 100% of what it actually is.

The picture to the right shows a Devil's Toenail. It's not really from the devil's foot. There are millions of them, and the devil would have had to spend all his time growing toenails and shedding them instead of going around being bad just to make a beach-load. They are actually Gryphaea, a type of oyster. With fossils, while there are some locally specific common names, it's less of an issue. Michigan's Petosky Stones are coral, Dudley Bugs are beautifully preserved Calymene trilobites, and there are a few more notable examples.

The crystal healers are very big on common names and I have a fair few as regular customers. I'm happy to help them find out the geological names of what they're looking for and to try and track down examples, but I feel sometimes the names are a little exploitative. I've seen some ugly rocks given appealing names as a sales aid. If you dig up a lump of murky brown calcite, it's going to be a bigger seller as 'Dolphin's Heart Calcite' than 'Mud-lump Calcite'. You get the idea.

No comments: