Sifu,
it is a clay type, just from the batch we had, it is more akin to a ball clay in it's properties.
Sticky, but not truly able to hand build shapes, needs to age and perhaps be exposed to more organic material.
Probably will cast or can be pressed into shape in a mould.
Maybe Al, had it fired to it's maturation point and the iron went from red back to yellow, which how our
sub-stoneware clays will do at 1180 deg.C and then they will proceed to bloat, before melting.
If your wondering, we have quite a few books on Clay and Pottery Clay Science, also did a couple years of
basic Geology.
However the idea behind a forum, is Communication and when one dips into Science, it will get confusing.
I raised the point of a clay because of an experience -
Back in 1985 or so, a local Chinese guy [ Trinidadian, just from China, Chinese parents ] grew about 5 J.B.pines
from seed, as they cannot be imported, supposed to carry diseases that affect citrus.
Anyhow, he is also a wire freak, give him a chance and he would wire you in place. [ age 80 something now ]
Well, he had these attractive pines in gravel and large earthenware pots.
Some where he got some information on Akadama, he is also a Kimura disciple, and took his trees, out of the
gravel and put them in the clay that comes with our decomposing sea bonded clay at Mayo.
For a few years, they grew, he also used some manure, which I gather kept the clay particulated, but eventually
the calcium/magnesium reaction failed [ please correct if I should have said organic reaction ] and one
day he had no J.B,pines.
The soil had returned to clay.
We know from his growing experience, that silica gravel works, and a small % of compost.
And that is why we avoid clay soils or clay loams.
Additionally, our checking of the soil cores of our 30 to 35 year old trees showed no formation of a tap root, as was
read about in Bonsai Today articles, just fine roots running around gravel and red brick. Plus, compost replacing
organic beads [ Humus, last stage of decomposition before becoming Metal Oxides ?
Roots are also unable to crush gravel or red brick, but perlite powders badly.
In a bind we can use a little peat moss, but our soil is very active, and with a little compost, in about 2 months,
it is beginning the organic bead cycle. Same for coco-peat.
We also have tunneling critters, that keep re-opening the soil.
You don't see them on the pure gravel based soils, where the use of inorganic fertiliser is practiced.
Guess this is why Paul [ Soil Scientist ?] left the Internet - probably just got fed up with the soil wars.
Good Day
Anthony
* Please note according to the research of a local Geologist our gravel may be silica bonded together [ is it in situ ? ]
by calcium/magnesium and is porous as well.
Not volcanic.
