What is this fruit that dyed my skin?

Last night I picked up some sort of fruit off the ground that grows in my friend's back yard. It was a light greenish-yellow color with a very hard skin, almost like a shell of some sort. It leaked a little bit of juice on my hand, and I wiped it off, and everything seemed fine. A few hours later before going to sleep I washed my hands and there was no markings or stains. I woke up this morning with a dark brownish-green stain all over my fingers and palm where the juice had touched my skin. I've tried everything I can think of to get the stain off: soap, nail polish remover, gasoline, paint thinner etc... I even tried sanding the area with a fine sandpaper... nothing will even lighten the stain. Does anyone know what sort of fruit this is, what it is named and how or when the stain will go away?What is this fruit that dyed my skin?
It sounds like it might be an immature black walnut. If you've only seen walnuts after they've been harvested, you would never know that the hard walnut shell with the nut inside comes encased in a green fruit-like covering. You could easily be getting some early walnuts falling off the tree at this time of year - not necessarily mature, but the tree will drop some of the nuts early. Did you ask your friend if they know what kind of tree it is?


Anyway, if it is black walnut, you are just going to have to wait until the stain fades away over time, unless you are desperate and want to risk making your skin cracked and dry by using some diluted bleach mixed with soap, scrubbing, and then rinsing thoroughly. I wouldn't advise it, though, because even so you'll have stains - just lighter in color. It does look like you've got real dirty hands, though, doesn't it?


By the way, in ';the olden days'; walnut hulls were used as dye for fabrics. Some handweavers and artisans still use them for this purpose, because it is a pretty darned permanent dye!