Do you know any lab where you can send a sample for finding out what organism it is?
Maybe I can contact the biology department at Gujarat University (I'm in Ahmedabad, India).
But that may take a while, so I could try putting a sample into a dish with some soil and humus to keep the colony active. But it may not be there when I go there tomorrow because it's a place where people are likely to step on it (it's between two parking bays).
I like it. Very photogenic.
I'm betting its organic, but can't tell from the pictures.
See what it looks like in a day or two.
In the picture, it looks like it is on top of the cement rather than within it. Yes?
It may be getting bigger, possibly growing but could be an inorganic getting larger too.
If its a slime mold aggregating (or perhaps a fungus coming together to make a mushroom or other fruiting body), it could get smaller and more concentrated where it is converging to.
It might be fluorescent, try a black lite at night.
Biological stains would also be interesting if you have any around.
I like @Swamp Thing's idea of putting a sample on potential media.
Put some dilute bleach on a small part of it and see what happens. Should kill live things.
Does water dissolve it? Inorganic salts?
Have a decent microscope? If so put some under that and look for cells.
If it is mineral efflorescence, how would those globules form? One possibility is that the tree branches out into whiskery dendrites, but at some point some droplets of dew nucleate onto the tips of the whiskers. A little salt could dissolve into the dew, which leaves a globule when it evaporates.
Or maybe it's just that the COVID has teamed up with some fungus or mold ... the Day of the Dendrids?