Oregon Akadama Candidate - 1st Look

In the BSOP monthly newsletter, longtime club member and ceramicist Mark Vossbrink offered for sale buckets of what he is calling Oregon Akadama. Being Akadama Curious, I immediately purchased a couple of buckets from him to see what he has found. The origins and location of the source material is still somewhat of a mystery shrouded in fine dusts.

First take on the material:

  1. Color difference from imported Akadama is dramatic. This material is much deeper/darker shade of reddish brown than imported Akadama. This color difference indicates that it is likely derived from weathered basalt and is much heavier in iron oxides than aluminum oxides.

Akadama on right

  1. Bulk density is comparable, but is 0.8 g/ml to Akadama’s 0.7 g/ml, which supports the idea that iron predominates over aluminum.

  2. Useable quantities in range of 1/4” to 1/20” (I don’t have a 1/16” screen) is about 90%, though there is some dust that comes with it.

  3. Significant amount of organic debris and evidence of roots in quite a lot of the material…speaks to surficial deposit, not buried. In the picture, you can clearly see that roots penetrate some grains and are still attached.

  4. Crush-ability is comparable to Akadama with some grains easily crushed and some grains more resistant to crushing by rolling between thumb and fingers.

This is an interesting candidate. Is it Akadama in the classic sense of the medium? No.
Is it a potential candidate for use in bonsai? Absolutely worth testing.
A good first attempt might be to combine it with pumice and a bit of scoria (40/40/20) and see what it does in the pot.

Next steps for me are to soak it and compare how a saturated sample compares to Akadama in durability and water absorption.


@DonPettit Thanks for the information. Do you plan to do saturated freeze/thaw as part of the durability test? That is a fairly challenging test for most soil components that absorb water.

It is a bit like the -65C/+150C for lots of electronic components including many automotive parts. That came from the temperature seen by a jet fighter scrambling from the desert surface to 65,000 ft. (19.6 km) in 15 minutes. I want a car that will do that!


Hadn’t thought of that, but sounds interesting. If I do, probably keep it down around 20 F, not -65 C!

Is the extra iron a good or a bad thing?

I would think it fine. I suspect this soil is similar (if not the same) to the soils found around the Salem Hills…which are iron-rich and world famous for viticulture.

I like the info above. Especially the color.
Chemical analysis? Ask the supplier?
Soak a 100 gm portion in 500 ml of water. Send the decant and a sample of dry off for simple inorganic solubles and surface XRF elemental analysis.
Only willing to be bit by high BORON once…

20F is probably fine. The key with the soils is to get the water to freeze since it expands upon freezing which may break the particles down.

The -65C/+150C was dry components. There is another wet test.

On a different note why are the rails in the US railroad 4 ft. 8.5 inches apart?

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And why do you ask young grasshopper?

This is amusing :slight_smile:

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I use the example in my engineering classes all of time. I use the final line of “The diameter of the space shuttle boosters are limited by a 2,000 year old Mil-Spec that was defined by horses a$$es”.