[fenman]

Hi,
I have just had a reasonable area of sandstone laid and we love the fern fossils which are green/black on some of the slabs.
When the time comes to cleaning will hypo bleach them out or are they a permanent feature.
David

[Dave Car]

Make sure you seal it with a good penetrating sealer.

[Smurf]

No hypo will not bleach them out as are millions of years old stone fossils which are part of the stone slab.

[Smudger]

Well done smurf - correct answer

Darran

[Smurf]

Well done smurf - correct answer

Darran

Why thank you smudger. They don't tend to turbo out either as I found out. lol

[Kev Martin]

Hi,
I have just had a reasonable area of sandstone laid and we love the fern fossils which are green/black on some of the slabs.
When the time comes to cleaning will hypo bleach them out or are they a permanent feature.
David

Seal the sandstone with Miracle 511 Sealer.  Depending on whether you want an original or wet look will decide which 511 product to choose.  The fossilised leaves will not be affected by cleaning as sandstone is formed through sedimentation and therefore the leaves and fossils you see in it are natural features

[Keiron Bradley]

I realise I'm a bit late to comment on this but as point of interest apparently many of these fossil-like markings are nothing of the sort,
I've read articles from several authoritative sources, including Paving Expert, who say that actually they are caused by a reaction from exposure to air for the first time in millions of years when quarried.

[Kev Martin]

I realise I'm a bit late to comment on this but as point of interest apparently many of these fossil-like markings are nothing of the sort,
I've read articles from several authoritative sources, including Paving Expert, who say that actually they are caused by a reaction from exposure to air for the first time in millions of years when quarried.

I am afraid to say that fossils are just that, Fossils!  They are in the stone!  I think you will find that what Paving Expert really mean to say is that often Fossils are exposed for the first time when the stone is newly quarried.

[Keiron Bradley]

No Kev, no disrespect intended but I know exactly what Paving Expert is saying as it is unambiguous and quite clear:

"Fossils (allegedly)
Many suppliers offer flagstone featuring these intriguing 'Fossils', which, admittedly, do look like ferns or some other simple plant from pre-history, and are a fascinating talking point when the client is showing off their new patio. However, they are actually a trace stain, created by a reaction of metallic oxides within the stone that has lain buried for millions of years before being exposed to the atmosphere when the stone flag was cleaved in the quarry.

Still, it's a nice thought, and makes the flags even more attractive! "


I was somewhat sceptical about this statement which is why I mentioned it. I wasn't making claims as to its accuracy, I was just saying it was an alternative view and from a very reputable source and was interested in some definitive clarification.
But I haven't misunderstood what they're saying.

[Kev Martin]

No Kev, no disrespect intended but I know exactly what Paving Expert is saying as it is unambiguous and quite clear:

"Fossils (allegedly)
Many suppliers offer flagstone featuring these intriguing 'Fossils', which, admittedly, do look like ferns or some other simple plant from pre-history, and are a fascinating talking point when the client is showing off their new patio. However, they are actually a trace stain, created by a reaction of metallic oxides within the stone that has lain buried for millions of years before being exposed to the atmosphere when the stone flag was cleaved in the quarry.

Still, it's a nice thought, and makes the flags even more attractive! "


I was somewhat sceptical about this statement which is why I mentioned it. I wasn't making claims as to its accuracy, I was just saying it was an alternative view and from a very reputable source and was interested in some definitive clarification.
But I haven't misunderstood what they're saying.

Here you go a bit of bedtime reading for you!

Pseudofossils

An example of a pseudofossil: Manganese dendrites on a limestone bedding plane from Solnhofen, Germany; scale in mm




Pseudofossils are visual patterns in rocks that are produced by geologic processes rather than biologic processes. They can easily be mistaken for real fossils. Some pseudofossils, such as dendrites, are formed by naturally occurring fissures in the rock that get filled up by percolating minerals. Other types of pseudofossils are kidney ore (round shapes in iron ore) and moss agates, which look like moss or plant leaves. Concretions, spherical or ovoid-shaped nodules found in some sedimentary strata, were once thought to be dinosaur eggs, and are often mistaken for fossils as well.