Great new book for people who like rocks, minerals and fossils

Veteran rock hunter, writer and geologist Garret Romaine's newest book is hot off the press. The Modern Rockhounding and Prospecting Handbook (Falcon Guides; $21.95) is a great reference to keep beside your armchair and in the RV (heck, get two copies!). The book provides the knowledge you need to go from a person who likes to pick up pretty rocks (or, are they stones? See Dr. Rock's previous post) to being an informed rock/mineral/fossil hunter. Garret's book uses down-to-earth language to give you a basic overview of the geologic processes relevant to collectors; a list of common minerals, crystals, rocks, fossils, and where to start looking for them; how to collect them safely and legally; how to work in the field and the essential tools you need, such as hammers, picks, and hand lenses; and he explains what to do with your prizes when you get home from your road trip. He also tells you how to gain more knowledge: how to obtain geologic maps and how to use them, a list of blogs, and references. The book also features short interviews withcollectors and geologists (including yours truly- blush).

Garret Romaine

Garret Romaine is an avid rockhound, fossil collector, and gem hunter; he has an  undergraduate degree in Geology, a Masters in Geography, and also an MBA. He is the author of Rockhounding Idaho and Rocks, Gems, and Minerals (both FalconGuides) as well as Gem Trails of Oregon and Gem Trails of Washington. He is also a columnist for Gold Prospectors magazine. He has a raft of YouTube videos about great outings in search of cool rocks and minerals:
http://www.youtube.com/results?search_query=Garret%27s+World+Of+Geology&sm=12
 

 

What is the difference between 'rock' and 'stone'?

Doctor Rock,
Do geologists distinguish between 'rocks' and 'stones'? Are these terms interchangeable?
Louisa Mayfair
Winnipeg

Louisa,

"Hey, Callie, is this a rock or a stone?'
"Not sure, Alec, let's ask Dr. Rock!"

Nice to hear from a reader in the 'True north strong and free'.
The difference depends on the context. In the informal usage, if you apply these terms to individual pebbles or boulders, then there's no difference. You can pick up a 'rock' and toss it in the creek, or do the same with a 'stone'. However, to a geologist, that pebble is made of 'rock'.'Rock' is the accepted scientific term for the material that forms the earth's crust and deeper layers. Geologists have a simple and somewhat facetious way to distinguish between 'rock' and 'stone'. If a price tag is attached, it is a 'stone'.

Here are definitions from the Dictionary of Geological Terms ('DGT') published by the American Geological Institute:

My friend Adena is standing behind a large conglomerate
boulder. This is a 'rock' using definition 1. of  'rock'.
According to definition 2 under 'stone', this
sedimentary rock consists of many rounded stones. Click
the photo for a closer look.

'Rock' 1. an aggregate of one or more minerals, e.g. granite, shale, marble or a body of undifferentiated mineral matter, e.g. obsidian, or of a solid organic material, e.g. coal. 2. Any prominent peak, cliff or promontory, usually bare, when considered as a mass, e.g. the Rock of Gibraltar. 3., A rocky mass lying at or near the surface of a body of water, or along a jagged coastline, esp. where dangerous to shipping. 4. a slang term for a gem or diamond.
(Doctor Rock adds: "I am aghast that they left 'Led Zeppelin' out of this definition! And what about the Stones?")

'Stone' 1. A general term for rock that is used in construction, either crushed for use as aggregate or cut into shaped blocks as dimensional stone. 2. One of the larger fragments in a variable matrix of a sedimentary rock. 3. A stony meteorite. 4. A cut and polished natural gemstone; a gem or precious stone.

There are interesting variations in nongeological dictionaries. For instance, the Random House Collegiate Dictionary says, among many other things, that 'stone' is "1. the hard substance, formed from mineral and earth material, of which rocks consist." (There are 27 more definitions!) Under 'rock', that dictionary's first definition coincides with definition 2. in the DGT. The second is the 'geological definition', essentially the same as 1. in DGT.