c/geology-rocks

Bought a $300 rock saw for my home collection and it was a huge mistake

Everyone online said a small lapidary saw was a must for trimming specimens. I saved up and got one, thinking I could clean up my own finds. It's loud, messy, and I used it maybe twice in a year because setting it up is such a pain in my garage. I should have just kept paying the local rock shop $10 to trim things for me. Anyone else buy a piece of gear they really regret for this hobby?

A guy at the Tucson Gem Show said 'that's not quartz, it's calcite' and handed me a bottle of vinegar

Serious question, a park ranger in Yosemite told me granite isn't always gray

He said the pink in some of the domes is from potassium feldspar, which made me realize I'd been ignoring a whole color family. What's the most surprising mineral color you've learned about?

Unpopular opinion: My cousin said all rocks are basically the same at a family picnic in Sedona.

We were hiking and I pointed out the red sandstone, and he just shrugged and said 'It's just a rock, Jenny.' I mean, that's like saying all trees are the same when you're in a redwood forest. Has anyone else had to deal with someone who just doesn't get it?

I used to think all gravel was basically the same for a driveway base

I was prepping a job in Flagstaff and the homeowner insisted on a specific crushed granite aggregate, which I thought was overkill. After seeing how it compacted and drained compared to the cheaper river rock I usually used, I get it now. Anyone have a go-to aggregate for high freeze-thaw areas?

TIL my vinegar test on a 'gold' nugget from the creek gave me a surprise

I was cleaning up some creek finds from a trip to the Blue Ridge foothills and had this one piece that looked like a small, rough gold nugget. I've always heard that a drop of white vinegar can help tell gold from pyrite, since pyrite will fizz. I put a drop on it and waited. No fizz at all, which got me excited. But then, after about a minute, the spot under the vinegar turned a dull, chalky white. That's not right for gold either. I looked it up and it turns out it was probably a piece of weathered galena, and the vinegar reacted with the lead to make lead carbonate. I thought the test was a simple yes or no, but it showed me there's a whole middle ground of weird mineral reactions. Has anyone else had a common field test backfire and show you something totally different?

I was sure the 'petrified wood' at the local rock shop was just dyed concrete

Took a piece to the university geology department, and a grad student showed me the preserved cell structure under a microscope. Anyone else have a find they were totally wrong about?

Bought a cheap rock tumbler for $60 and it broke after two cycles.

The motor burned out and ruined a batch of agates from Lake Superior. Anyone know a good brand that can handle harder stones?

Serious question, I thought the whole 'petrified wood is just rock' thing was a scam for tourists.

Then I went to the Petrified Forest National Park in Arizona and saw a log that weighed over 200 pounds. Picked it up, felt the weight, saw the crystal structure. Totally stone. Blew my mind. So what's something in geology you were sure was fake until you saw proof?

Just hit 1000 miles on my rock hammer's current handle and it hasn't even chipped

I've been logging every field day with my Estwing since I started my project in the Arizona desert last year, and hitting that number made me realize how much I used to underestimate good tool maintenance. What's the highest mileage you've gotten out of a single geology tool before it needed a major fix or replacement?

My buddy said my rock ID was all about color, and he was totally right

I was showing off a piece of granite I found near Boulder, calling it 'pink granite' because of the feldspar. My friend, who's a geology student, just looked at it and said, 'Derek, you're just naming colors. What about the texture and the actual mineral grains?' He was right. I was skipping the real stuff. So now, I carry a cheap 10x hand lens and a steel nail for a hardness test. Last weekend, I found a dark rock and instead of calling it 'black rock,' I checked. It scratched glass, had no cleavage, and was fine-grained. Turns out it was basalt. It's way more fun to actually figure it out than just guess. What's one simple test you always do first when you find a new rock?

I thought the 'glacial erratic' in my town park was just a big rock someone dumped there.

For years I walked past this huge boulder in the park thinking it was leftover from some construction project. Then I went to a local geology talk at the library and the speaker used it as an example. He said it's granite, but the bedrock here is all shale, and it was carried over 200 miles by an ice sheet. Seeing the map of the ice flow path made it click. Anyone know of other good examples of erratics in the Midwest?

Shoutout to the park ranger at Bryce Canyon who explained hoodoo formation

He pointed at a specific rock layer and said 'see that red cap? That's harder limestone protecting the softer stuff below from rain.' It clicked for me right there. Anyone know other parks with really clear examples of differential erosion?

Took my old rock hammer vs a new Estwing to a basalt outcrop near Bend

The Estwing's one piece steel handle didn't wobble after 20 solid hits, while my old one with the wooden handle started coming loose. Anyone have a favorite hammer for tough igneous stuff?

Vent: My neighbor just called all the rocks in my garden 'plain old gravel'

I was showing off my new rock garden, which has some really cool banded chert and a piece of petrified wood I got from a trip to the Arizona desert. He looked at it for a second and said, 'Looks like the stuff they put in driveways.' It just made me realize how much you have to know to really see what's special (like the tiny quartz veins in the chert). Has anyone else had someone totally miss the beauty in a rock you were proud of?

A customer brought in a rock he found near the shop and asked if it was a meteorite

It happened last Tuesday, right at the front counter. He pulled this dark, heavy lump from his pocket and said, 'Found this in the gravel lot next door, think I got lucky?' I had to tell him it was just slag from old iron smelting, which is super common around here. You could see the little bubbles and the way it fractured. He looked a bit bummed, but we ended up talking for like twenty minutes about how to spot real space rocks versus industrial leftovers. Anyone else have a go-to trick for telling slag from something more exciting?

Found a piece of petrified wood in a creek bed near Flagstaff that everyone kept calling a fossil. It's not, and the difference matters for figuring out the area's history.

Everyone says you need a proper rock hammer to split shale, but a simple putty knife worked for me.

I was out near Sedona last month and needed a fresh surface on some shale layers, but I'd forgotten my Estwing. I tried a stiff putty knife from my truck and it slid right into the bedding plane, giving me a perfect split. Has anyone else found a basic tool that worked when the 'right' one wasn't there?

I've always just used a regular hammer for my rock samples, but my professor lent me a proper geological hammer for a field trip to the Badlands.

The difference in clean, controlled breaks was night and day, especially on the brittle shale layers. Anyone have a favorite brand or style of rock hammer they swear by?

Don't buy those cheap rock identification kits online

I spent $45 on a kit from some random site that promised to help me identify local minerals. The hardness picks were made of soft metal that bent on quartz, and the streak plates were just painted ceramic tiles. I wasted a whole weekend trying to make it work before I gave up and tossed it. Has anyone found a decent starter kit that won't fall apart?

Appreciation post: My old rock hammer from college finally gave out after 15 years, so I bought a new Estwing model last month.

The new one's better balance and shock-absorbing grip made a huge difference during a full day of sampling in the Mojave, reducing my hand fatigue by at least half, so what's your favorite field tool upgrade that actually changed your work?

Hot take: my $80 rock hammer was a total waste, but my friend says I'm crazy

I mean, I bought it for a field trip to the Arizona desert last month and barely used it. My friend swears by his for splitting samples, but I just ended up using a regular hammer from my garage. Anyone have a better tool for basic rock collecting?

Found a surprising detail about the stones in my local creek

I was reading a county survey from 1978 and learned the rounded granite cobbles in Miller Creek are actually glacial erratics, carried over 50 miles from the Sierra Nevada. Has anyone else found unexpected origins for common local rocks?

I chose a rock hammer over a chisel for my first fossil hunt in Utah

Everyone in my group said a chisel was better for splitting shale, but I went with a 22 oz Estwing hammer instead. It let me break through a tough limestone layer that was covering the fossil bed. I found three small trilobites after about two hours of work. Has anyone else picked the 'wrong' tool and had it work out better?

Pro tip from a ranger about finding agates

A park ranger in Oregon told me to search right after a rain, and I found three small carnelians in 20 minutes. What's the best piece of advice you've gotten for a specific hunt?