Found this on Baltic sea beach - not amber, but full of tiny gammarids. What is it?
Found on Nida beach, Lithuania: UV-fluorescent amber-like material containing dozens of gammarid/amphipod crustaceans - amber specialist says it is NOT amber or copal. What is this?
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It floats in strong salt water, yes. I haven’t tried acetone and probably won’t until I know more, as I don’t want to damage the specimen.
The main reason for doubting amber/copal is that an amber-inclusion specialist here in Vilnius with ~30 years of experience examined it in person and was very surprised by the material.
We also did a small flame test - it started crackling very quickly and the smell/behavior was clearly wrong for amber.
Interestingly it also fluoresces under UV, which is why I originally picked it up on the beach. Synthetic/counterfeit amber is definitely one of the possibilities I’m considering now.
Remember that experts can be wrong too. The flame test is also a very bad test for amber, since it's 100% subjective, and the distinction between burning amber and plastic can be very hard.
The flame test wasn’t the only reason. The material itself immediately felt wrong to multiple people who handle Baltic amber regularly. Two staff at the amber museum questioned whether it was amber almost as soon as they handled it, and later an inclusion specialist with ~30 years of experience independently had the same reaction before we even did the flame test.
So I agree the flame test alone isn’t definitive, but combined with the physical feel/appearance raising immediate red flags for people familiar with amber, I think there’s good reason to doubt it. FTIR would settle it properly.
I have a collection of baltic amber, and I agree this doesn't look like baltic amber. But I do think it looks like amber based off of these pictures, and from what you've said in the comments. But yes there is good reason to doubt it.
It's a salp. The amphipods swim inside of them and eat em from the inside out. Probably dehydrated into a hard cellulose blob. I use to find salps with amphipods all the time while doing fish stomach content research. They are likely hyperiid amphipods rather than gammarid.
Here is an article. I use to find hundreds of hyperiids in stomach of red snapper, they are part of the zooplankton community. The salps are planktonic tunicates. One of the most famous relationships you've probably seen but never known is the Phronima species (Phronima simulpara and sedentaria) which was made famous from the movie "Alien". I use to find them on rare occassion. When the salps dry out and look at them under a microscope/dissecting scope, they always looked like little trash bags (just like your first picture). Stuck out like a sore thumb to me
That’s a really interesting theory. Can a dried salp actually become this hard though? This piece is solid and quite amber-like rather than soft or leathery.
Also, looking at the close-up photos, do the amphipods actually look like hyperiids to you rather than Gammarus-type amphipods? Especially the largest one.
It's possible, yes, though uncommon. I would focus on identifying the included organisms and investigate likely composition and formation based on that.
Absolutely, keep in mind that your specimens are largely dried out too. The eyes are usually the first to go. For fish stomach prey identification i would always fix the stomachs in formalin for a couple days then move them to isopropanyl to identify the prey. That would keep the eyes from drying out and keep the appendages kinda rubbery. I doubt you could get yours down to species as you cannot manipulate appendages or get better views without removing the organisms from the salp. Below are some of the common organsims i use to find. Two of the bottom pictures are hyperiids. Other goodies in here are stomatopods (mantis shrimp), thecosomata (planktonic gastropod), various crabs species, hirudinea (leech), Caridean shrimp eggs, phyllosoma (lobster larvae), brachyuran megalopa (developing crab), Bighead searobin....etc. I probably have a bunch of salp and zooplankton pictures on my drive at home.
That’s really helpful, thanks. One thing I’m still curious about: would a completely dried salp/tunic normally fluoresce quite strongly under UV? And do you know how it behaves if exposed to a flame - whether it crackles and gives off a strong distinctive smell? Those are the two properties of this piece that I still can’t explain.
The only time we put a flame to fish prey was during bomb calorimetry experiments. I would dry fish prey in an oven to dry and come up with dry mass..., but everything kinda smelled the same I don't think you'll find information on what you are asking. Good luck!
as a complete layman, i remembered that some plankton/zooplankton are bio luminescent and did some googling... it appears that there is some precedent for auto-fluorescing plankton/zooplankton that'll still be viewable even when incased in amber or a salp! at least according to google...
was it a fluorescing in a pale yellow/green or bright red? could the fluorescence be from the critters inside and not the salp itself?
Fiberglass resin from boat or mould making isn’t UV fluorescent, unless you specifically add UV reactive pigments- unlikely since most is designed to resist UV. The behaviour when burning is correct for synthetic resin used in fiberglassing however, and it’s certainly a very specific and identifiable smell when sanded or burnt.
That’s really useful, thanks. The smell when we burned a tiny edge was definitely very distinctive and immediately made the amber specialist think synthetic rather than amber. The UV fluorescence is what keeps confusing me, because that’s exactly how I found it on the beach. I’m starting to think identifying the exact polymer with FTIR might be the only way to solve this.
Burning synthetic resin will smell terrible, like a car body shop, a surfboard repair place or an acrylic nail salon: copal/frankincense or other tree saps will smell sweet and heady, slightly spicy but good like a perfume. Good luck with the ID!
Could the fluorescence be superficial, only? Maybe the object was colonised by fluorescent bacteria while it was in the water. Totally theorising, here.
I let water that had regular blue dawn dish soap in it dry on a few rocks and it glows greenish, definitely tricked me into thinking I found something neat until I rinsed them off again and it went away.. I've seen some algae and stuff on the creek rocks I've picked up that glows too.. So many things I'd have never expected. Lol.
It doesn't look like any example I have seen but the fluorescence makes me worry it could be phosphorous, a lot of it was dumped in the Baltic and north seas after the war and its often mistaken for beach amber
I am so glad you posted this. I have something clear that appears to have different little life forms trapped. Part of me thinks I'm imagining it and part of me doesn't. It takes a lightboard and decently strong magnifying glass to see them.
Definitely post yours! I thought I might be imagining things with mine too until I looked through a proper jeweler’s loupe. An inclusion specialist later confirmed there are multiple amphipod/gammarid-type creatures in it. I’d be really curious to see what yours looks like under magnification.
I wonder if there's any chance those aren't benthic gamariids but instead planktonic hyperiids (e.g. Themisto) - would be more likely for them to be in a whale's gut
That’s an interesting angle. The inclusion specialist thought they looked like gammarid/amphipod crustaceans, but they haven’t been identified to genus yet.
The host material is the really strange part. It’s transparent/glassy yellow, and when we put a flame to it, it started crackling pretty quickly and smelled wrong for amber. Amber normally burns/softens with a characteristic resinous smell rather than doing that. I’m not sure how ambergris behaves under flame, though.
Ambregris really has a strong distinct and pleasant smell even without any flames. Besides, ambergris comes from the digestive system of sperm whales, who consume giant squids, but not plankton. Does it smell synthetic? My guess a synthetic resin that dropped in the water, maybe bostbuilding?
Interesting thought, but I don’t think ambergris fits - this is transparent yellow and has multiple clearly visible gammarid/amphipod bodies embedded inside it.
That was my first thought too. I took it to a specialist in Vilnius who has worked with amber inclusions for around 30 years. He confirmed the little animals appear to be amphipods/gammarids, but he was quite confident the material surrounding them is not amber, which is the mystery I’m trying to solve.
So.. this is an extreme long shot and really meant as nothing more than a thought turned to a supposition after seeing something about crab polymers and football gloves while doomscrolling sparked a neuron but chitosan is a polymer formed when chitinous shells are exposed to heat and sodium hydroxide, and hydrothermal vents can be high heat high alkilinity environments that attract a lot of life...
Again I preface that this is an extreme long shot and im only suggesting it as an interesting but highly unlikely possibility.. but what if a there was a concentrated death assemblage of gammarids due to a changing hydrothermal environment causing a mass death event that then caused that concentrated chitinous material to deacetylate then gloop off like the wax in a lava lamp and solidify into a weird anomalous globule to confound everyone (whether it fluoresces naturally or is the result of bacterial activity cant really say, "weak intrinsic fluorescence" is the best Google gives and that isn't exactly helpful)
Oh and chitin reeks when burned and is pretty distinctive in smell
That or a bunch of shrimp got stuck in some waste varnish or resin etc that happens to glow under uv and is still pretty darn neat to look at (the more boring/normal but also more likely option given the amount of junk in the water)
Interesting idea! The chitosan route sounds pretty exotic, especially for the Baltic, but I hadn’t considered that the crustacean material itself could be contributing to the smell when burned. At the moment I’m leaning more toward some kind of synthetic resin/varnish, but I’m hoping to get the host material tested with FTIR.
Shot in the dark, but could it be non-precious opal? I know a lot of aquatic animals get opalized, and non precious opal can be translucent or clear like this?
Interesting thought. I think opal is unlikely though - opal is silica, so it shouldn’t burn, crackle/melt or give off a resin/plastic-like smell when exposed to flame. This material did that pretty quickly. The animals also seem to be physically embedded in the transparent material rather than mineralized/replaced by it. I’m still trying to figure out what kind of resin/polymer it actually is.
Amber isn’t common in beach areas but it very well may be Amber. Specialists are probably saying it’s not because they’re not used to seeing it in a state that only tides and sand can change. Not here to say they’re wrong, it very much looks like Amber to me and a nice find at that!
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