u/Overall_Purpose51

I've had this natural gourd (calabash) for a while and noticed green-grey discoloration building up on the inside walls — not on the bottom. Trying to figure out if this is mold or just normal buildup/patina from the mate, and I'd really appreciate a second opinion from people with more experience.

Some details that might help:

• The discoloration is green-grey and patchy. To me it does NOT look fuzzy — I think the texture is just the rough, fibrous surface of the gourd wall that happened to discolor, but I'd like others to judge from the photos.
• It smells like tobacco/mate/wood — not musty, moldy, or damp-earthy.
• I can't scrape or scratch it off. It seems to sit in the material rather than on top of it.
• There are a few small dark specks, but I think those are just leftover mate residue I didn't rinse out well enough.
• It's a natural gourd, not palo santo, glass, or steel.

The smell and the fact that I can't scrape anything off make me lean toward this being patina rather than mold, but I'm not confident enough to keep drinking from it without a second opinion.

Photos attached (including a sharp close-up). Would love to hear whether this looks like mold I should toss the gourd over, or if it's just patina I can keep drinking from. Thanks!