Thread: Extreme Colour Change

Here are some pic of Columbian Purpleheart (a fine grained Peltogyne spp) that I cut today for pen blanks.
They all show wavy grain and that wonderful bright purple colour ... in time!
Here is some progression in colour

Col Phrt .jpg

Above 30 mins after cutting ... a pale pink brown

Col Phrt +6 hrs .jpg

Above: 5 hrs later....

Col Pht.jpg

Above: after 2 weeks . Coated with a surface finish on left side.

Australian Waddywood (Acacia peuce) heartwood also changes - from a dark greenish brown-black when freshly cut as I did today, to a dark purple over a few days. Pics below

waddywd.jpg
Above: 2 pieces of freshly cut figured waddywood, one with sapwood showing wavy grain. Note its strange greenish colour which changes to the dark purple (see on large old block below)

Waddywd .jpg

Above: same 2 pen blanks on a large (very old block of ancient Waddywood) showing its dark purple surface wood colour.
In a few days the pen blanks will gradually become a dark purple.

Purple Gidgee (Acacia crombiei) also changes like this startng at the interface between sapwood and heartwood.

Great thread Euge.
That Gombiera looks interesting, pity the yellow bits will also darken when exposed.
I have some Carbeen (I think) that shows similar splotches on the end grain when cut, but the colours are light brown with dark brown outside.
Will have a look for some on the weekend and post a pic if I can find it.

Oops put the message in wrong thread. Deleted

Originally Posted by Ironwood

Great thread Euge.
That Gombiera looks interesting, pity the yellow bits will also darken when exposed.
I have some Carbeen (I think) that shows similar splotches on the end grain when cut, but the colours are light brown with dark brown outside.
Will have a look for some on the weekend and post a pic if I can find it.

Gidday Ironwood, I have been unaware about Carbeen changing, although I was aware its wood became a mid chocolate brown in colour when aged. If you ever have pics (befre and after or the transition zone) I would like to see them, to illustate articles or papers. Or any other woods you recall that show more dramatic changes in colour on exposure to light. Thanks

Maclura pomifera, Osage Orange wood , changes from a deliteful golden-yellow when freshly cut to a dirty brown after a few weeks. Mulberry wood (Morus sp) similarly darken to a brown. Some woods just bleach become pale and washed-out on exposure to light. Purple Gidgee (once its turned purple) bleaches and Pink Ivory does too. In contrast the oily Dalbergias (eg Cocobolo) become VERY dark on aging but its the coloured woods which show more rapid changes I am most interested in.

Here (below) is a Waddywood pen blank end grain showing the lovely TRANSITION zone colour change between sapwood and heartwood.
This transition seems charcateristic of this species (A. peuce) as well as A. crombiei (Pink or Purple Gidgee). I have not seen it in the two other 2 purple Acacias

Waddy end.jpg

Originally Posted by Euge

Gidday Ironwood, I have been unaware about Carbeen changing, although I was aware its wood became a mid chocolate brown in colour when aged. If you ever have pics (befre and after or the transition zone) I would like to see them, to illustate articles or papers. Or any other woods you recall that show more dramatic changes in colour on exposure to light. Thanks

There are some bits of Carbeen in one of my sheds, I just have to find it amongst the mountains of other stuff. If I can find some tomorrow, I will cut a piece to expose the change in colour and post some pics.

Are you looking for timber that just oxidises a different colour on the exposed surface as well, or just stuff that changes colour further in ?

Thanks Ironwood. Look forward to any pics of carbeen.

Interested in surface changes or deep seated effects. Surface effects tend to be light induced. Interior maybe due to oxygen diffusing in. Just one theory.?

Here is the end grain of waddywood 2 days later.
The coloured transition zone is more obvious as a coloured band. This is great when shown in a pen or other turning!

Waddy.jpg

Offcut/waste out of a Carbeen slab, 32mm thick. I can't remember how long since I cut up this slab, would be at least 5 months.
This is a freshly cut slice off one end. 2nd pic has been wet.

DSC_9413.jpg

DSC_9414.jpg

Cooktown Ironwood Oxidises a dark chocolatey maroon.
DSC_9417.jpg

Originally Posted by Ironwood

Offcut/waste out of a Carbeen slab, 32mm thick. I can't remember how long since I cut up this slab, would be at least 5 months.
This is a freshly cut slice off one end. 2nd pic has been wet.

DSC_9413.jpg

DSC_9414.jpg

Thanks Ironwood, that's a very similar effect (oxidative darkening / colour change) and quite well demonstrated with your Carbeen. I wonder if other Corymbia spp are prone to that eg maybe spotted gum does the same? Thanks for bringing it to my attention. Probably caused by oxygen (not light) and interesting to see darkening in the deep check with darkening along both sides of the 2 check. May be worth exploring further. Hope others chime in with examples or ideas.

while showing pics of waddy wood slowly changing colour,-I came across this pic of another purple Acacia wood which is as seen here ... a bright purple in the heartwood AND what appears to be a pale purple halo which may be heartwood pigment may have diffused into sapwood OR sapwood transferring the pigment (a peltogyne reated pigment) into the heartwood

A carne..jpg

The continued monitoring of the colour change in waddywood cut about 1 week ago. 2 sections shown. Using ambient light not direct sunlight

Waddy 1 wk.jpg

Waddywood (Acacia peuce) .. with a pale sapwood band becoming more prominent - section is about 28 x 28 mm


Waddy -1 wk.jpg