Obviously, a Geiger Counter such as the IdealRatio Rodnik 3 doesn't really prove it's worth until it finds something radioactive, so some reviewers of these devices (not just myself) will ask the rhetorical question "Have I found anything radioactive?"
 
Well... I recently went on vacation, and took my Rodnik 3 with me.  It was great that it was so portable.  And yes, I did find quite a few radioactive things -- some of them were impressively radioactive.
 
Or vacation was a long road trip, with several stops along a significant portion of the Eastern Seaboard of the United States.
 
The first stop was the Daytona Flea Market in Florida. https://daytonafleamarket.com/ .  Antique hunters will want to proceed all the way to the back (north end) of the market.  There is a vendor there that sells antique glassware.  He already knows me and my DRSB-88 radiation detector.  The "Radioactive Green Cat" mentioned in the review was purchased from his antiques tent, and yes, he still has numerous Vaseline glass pieces that the Rodnik 3 responded to. I asked him about Fiestaware https://en.wikipedia.org/wiki/Fiesta_(dinnerware)#Radioactive_glazes , and he lead me to a complete place setting of red authentic antique Fiestaware.  It was mildly radioactive, but not really that impressive. We began talking about other items that may have a radioactive glazing.  He mentioned that he thought some yellow glazings were also radioactive.  We tested several pieces, but nothing seemed to get the Rodnik 3 excited.  Then, totally at random, I held the Rodnik 3 near a rather ugly clay pitcher with a beige glazing, and glazing on the front in other colors depicting fruit, including intense (for the age) purple grapes.  The Rodnik 3 began counting events in a continuous stream, and soon went to alarm mode.  I am not sure if the pitcher itself was made of a radioactive clay, or if it was the glazings.
 
The pitcher was large, ugly, and while the seller was willing to negotiate, it just was not something that I actually wanted to take with me on the rest of the trip.
 
The next real destination for our trip was Washington, DC -- more specifically, the Smithsonian National Museum of Natural History.  This museum (the most visited museum in the world) has an extensive section about minerals and gems, including a display dedicated to radioactive minerals.  When I saw what the display was about, I of course thought of the Rodnik 3 in my pocket.  As soon as I thought of it, I realized it was already in alarm mode in my pocket.
 

The Rodnik 3 responding the a display of Radioactive minerals at the Smithsonian National Museum of Natural History, Washington, DC, USA.
 
This showed 2 things -- First, it was the first (and only) time it actually warned me of radiation exposure, as opposed to me actively testing an object.  Second, I did not hear it alarming until I thought of it. As I mentioned in the review, it was not loud enough to get my attention over the background noise of the crowded museum.  (More about the Smithsonian display in a later post. See Below.)
 
The return trip provided another opportunity for the Rodnik 3. By sheer chance, we happened upon the Black Rose Antiques and Collectibles Mall in Phillipsburg, New Jersey. https://www.blackroseantiques.com/ .  Several of the booths had items that really got the attention of the Rodnik 3.  There were several antique clocks with Radium dials, and the usual assortment of Fiestaware and Vaseline glass.  But in 2 separate booths, there were identical red-orange pitchers that immediately put the Rodnik 3 in alarm mode, even from several feet away.  Neither of these pitchers had any markings, so they were apparently not actual Fiestaware, but they must have had significant Uranium in the red-orange glazing.
 
There was also another small vase that caused the Rodnik 3 to immediately go into a constant stream of counts, and almost immediately alarm.  This piece was particularly interesting because nothing about it's appearance gave a clue to it's radioactivity.  It did not have a shiny glazing at all, and it was not red, orange, or yellow.  If anyone ever buys it, they may never be aware of it's radioactivity.
 
The Black Rose Antiques and Collectibles Mall was a really cool stop, and the Rodnik 3 added a whole new dimension to browsing the dozens of overstocked vendor booths.
 
Note: Pictures of the radioactive antiques I did not buy are not included, since many antique vendors do not like people taking pictures of their offerings.

Another note on displays pertaining to Radiation at the Smithsonian National Museum of Natural History.
 
In another room, there is a different display on radiation.  This display contains an analog radiation meter (Geiger counter) and a chunk of radioactive ore attached to a rotating disk.  The intent is to show that the Geiger counter registers as the ore passes near the Geiger probe.
 
This is not the display I am referring to in the above posts.  While the radiation in front of the display with the rotating ore was detectable as I stood in front of this display, it was no where near the levels near the display of radioactive minerals in the minerals and gems area.
 
 

Here's another "Have I Found Anything Radioactive?"
 
I did:
 

 
In this picture, my IdealRatio Rodnik 3 is showing approximately 50x background a few centimeters from a rather unremarkable looking rock.
 
Based on a (very) little research I did while writing this post, I believe this may be a specimen of coffinite.
 
Before you ask why I would own something that is highly radioactive, and with a name that has a close association with death, I should mention that coffinite is named after American geologist Reuben Clare Coffin.  The name of the mineral is just a coincidence of a rather unfortunate last name.  While coffinite does contain uranium, the name was not meant to portray this mineral as any more or less dangerous than any other naturally occurring mineral that contains radioactive elements.
 
The assumption that the stone in the picture is coffinite is based on pictures from a Google Images search that seem to show similar grayish rocks with traces of yellow crystals.  In addition, coffinite is the 2nd most prevalent uranium-containing mineral, so simple statistics show good odds that it is in fact coffinite.
 
So how did I come to posses this bit of hyperactive nature?
 
I would have never found this stone without my IdealRatio Rodnik 3.  I was at my local flea market.  There are 2 vendors there that specifically sell crystals, stones and minerals, but this rock didn't come from them.  I did buy a piece of tumbled green apatite from the larger vendor.  I learned that green apatite seems to generally be more radioactive than blue apatite.
 
I also purchased a tumbled malachite stone - not for it's radioactivity (it isn't radioactive), but for the name association with another project covered here on Linuxslate.com.
 
Having passed the crystal/stone vendors, and in fact reached the very end of the market, I came across a man with several full tables of random rocks, as well as quite a lot of abalone shells.
 
I don't remember if it was something the seller said, a sign or label, or just the general look of the various rocks, but I got the impression that the rocks were from the Western United States.
 
I waved my Rodnik 3 over the boxes, and it gave a flew clicks over a specific corner of one box.  Of course random events of cosmic or local nature can cause a momentary jump in counts, so I waived the counter over the same area again, and again it reacted. I picked up some rocks in that part of the box, but when  I tested those rocks while holding them away from the box, my Rodnik 3 began to decrease back toward a normal background reading.  With some of the rocks moved away, I again held the Rodnik 3 over the box.  It began a steady stream of beeps followed almost immediately by the alarm mode.
 
Something in the box was "hot", and the other rocks had basically been shielding it.  So you basically know the full story.  The source of the radioactivity was the small stone pictured above.  I paid the man $3 and took my rock home with me (but not in my pocket.)
 
If I see the same vendor again, I will ask him if he knows any more about were the rocks came from.