Dear Jose,

Thank you for contacting Mearto with your appraisal inquiry.

The presented object appears to be fossil cropolite or similar mineralized probably organic material or mineral.
This piece is in good condition and there is no serious damage visible in the images provided.
A fair market estimation would be between 0 to 20 USD.
This estimate is based on actual recent past recorded auction sales of comparable items. Retail "asking prices" can be higher and may vary.

With kind regards,
Georg