There was a big pecan tree that fell on my grandfathers places 3 or 4 years ago. My cousin that lives there now drug most of it off but I saved a big log to do something with in the future. It's been laying in my parents barn ever since.
I want to have a knife made and thought it would be cool to use this wood for the scales. I'm home this weekend for Christmas and decided to cut some chunks off. I think this will look good. What say you experts?

Outstanding you have some spalting developing. There's some serious money in that wood if it's milled right.

https://en.wikipedia.org/wiki/Spalting

Should I let it continue to age? Will the spalting continue to spread with time? If so I'll just take a little for a knife and leave the rest.

I would think that it would; it's fungus that will grow.

Just remember spalting is an early stage of decomposition. it will spread, but you need to catch it and stop it before it's too far gone. Generally it's stopped by drying the wood. A small quantity is easily done in a kitchen oven.

If it were me I'd find a place that could process them correctly and salvage as much of it as possible. You can sure sell them. I've seen spalted pecan scales sell for $25 to $30.00.

Brought several pieces back to Texas. Plan to carry it to MikeC soon for a knife order.

It's got some cracks (checking?) I'm hoping he can use it.

I think that we can work around the checking.

I like exotic wood scales, that pecan is awesome