Happy Wednesday -
Just thought I would post some photos from years ago in the Laingsburg Karoo - teaching geology here is what got me started learning about succulents and I didn't know anything about them at the time, hoping somebody here might be able to identify some of these plants. Please excuse the rocks that may have been the subject of the photos!

From what i can tell you,
a Mesembryanthemum (magenta flower)
an aloe (5th photo)
2 crassulas, crassula pyramidalis, im not sure about the other one
a gazania(yellow flower).
Not sure what the blue thing is, the first looks like a parasitic plant, or maybe a bulb.
And I cant help you with the rock. But perhaps you can help with something on the covid diversion thead.

Blue thing is aptosimum indivisum

First is Harveya squamosa

skopjecollection said:From what i can tell you,
a Mesembryanthemum (magenta flower)
an aloe (5th photo)
2 crassulas, crassula pyramidalis, im not sure about the other one
a gazania(yellow flower).
Not sure what the blue thing is, the first looks like a parasitic plant, or maybe a bulb.
And I cant help you with the rock. But perhaps you can help with something on the covid diversion thead.

Thank you~!!!
The rock is a radial phosphate nodule in some weird anoxic shales, formed during the recession of the Dwyka glaciation about 325 Million years ago..... strange, but not as strange as Harveya which I now have to read up on. Thank you so much! The unknown crassula is called "sosatie bos" locally.... kebab bush. C. perforata?

Rockcozy said:

Thank you~!!!
The rock is a radial phosphate nodule in some weird anoxic shales, formed during the recession of the Dwyka glaciation about 325 Million years ago..... strange, but not as strange as Harveya which I now have to read up on. Thank you so much! The unknown crassula is called "sosatie bos" locally.... kebab bush. C. perforata?

Rupestris, Crassula rupestris. Look similar but opalscent instead of opaque.

This is what I wanted to ask you about



Its on limestone. No idea where its from, its not from nature(likely used for wall building).

skopjecollection said:This is what I wanted to ask you about



Its on limestone. No idea where its from, its not from nature(likely used for wall building).

OOOh interesting. it doesn't look like a carbonate crystal shape (which would be most common because it's the same mineral that forms the stone). Is it soft, do any pieces come off when you scrape the crystals? If you can get a sharper close up picture that would help

Rockcozy said:

OOOh interesting. it doesn't look like a carbonate crystal shape (which would be most common because it's the same mineral that forms the stone). Is it soft, do any pieces come off when you scrape the crystals? If you can get a sharper close up picture that would help

Nope. Hard, very firm, and not brittle(like calcite). Sharper picture is a no can do, phone is just bad at closeups.

I think it is a calcium carbonate vein filling, probably aragonite, which can have that color and appearance and is not very crumbly. The rock was split along the vein giving this surface.

Another thing I thought of was travertine.

Well the color reminds me a scheelite but that would be unusual to find in an ordinary limestone used for walls because it is an ore mineral of tungsten. Habit could be an epidote mineral but the color would be a bit unusual for epidote. So after that thinking aloud it turns out I am not sure what your mineral is.

mcvansoest said:I think it is a calcium carbonate vein filling, probably aragonite, which can have that color and appearance and is not very crumbly. The rock was split along the vein giving this surface.

Another thing I thought of was travertine.

If it's one of those carbonate minerals it should scratch easily with a knife, and you're right I've seen aragonite this color before.

mcvansoest said:I think it is a calcium carbonate vein filling, probably aragonite, which can have that color and appearance and is not very crumbly. The rock was split along the vein giving this surface.

Another thing I thought of was travertine.

Well, it can be cut, and ive managed to break off a small piece. Inside was clearer, but its still the same color.
It still gave more resistance than plain calcite. Im not breaking it any further.

Perhaps dolomite

Some info, there may be a mine for chromium(or ferosilicate ore) nearby.

Dolomite is harder than calcite.

So that mine could mean that you end up with veins filled with mineralising fluids these might still deposit fairly common minerals, but they may have impurities that give it color that you may not normally see. Iron oxide will tend to give calcium carbonate minerals this kind of orangy brown color.

Any chance you have some relatively strong acid available (10% HCl would be best, but some times you can get somewhat or a reaction from warm vinegar on calcium carbonate)?

mcvansoest said:Dolomite is harder than calcite.

So that mine could mean that you end up with veins filled with mineralising fluids these might still deposit fairly common minerals, but they may have impurities that give it color that you may not normally see. Iron oxide will tend to give calcium carbonate minerals this kind of orangy brown color.

Any chance you have some relatively strong acid available (10% HCl would be best, but some times you can get somewhat or a reaction from warm vinegar on calcium carbonate)?

Well, its fizzing in vinegar.

It's probably aragonite or calcite then (they have identical chemistry and both fizz vigorously). But also, dust from the limestone might be on the crystals, so to be absolutely sure, give the whole rock it a good rinse under the tap and if it still fizzes, that's it. Dolomite fizzes very weakly or not at all unless powdered or scratched. Dolomite is a bit harder than calcite but both are pretty soft and scratch easily. The habit looks more like aragonite but I'm not sure.

Rockcozy said:It's probably aragonite or calcite then (they have identical chemistry and both fizz vigorously). But also, dust from the limestone might be on the crystals, so to be absolutely sure, give the whole rock it a good rinse under the tap and if it still fizzes, that's it. Dolomite fizzes very weakly or not at all unless powdered or scratched. Dolomite is a bit harder than calcite but both are pretty soft and scratch easily. The habit looks more like aragonite but I'm not sure.

Stopped fizzing after a while. Way before cleaning.

Great pics, really like number 3