કાજલ તજે ન શામતા, મોતી તજે ન શ્વેત;

kājala tajē na śāmatā, mōtī tajē na śvēta;

Literally: Kajal does not abandon its blackness, a pearl does not abandon its whiteness;
What it means: People cannot change their fundamental nature, as the wicked will never abandon their wickedness and the virtuous will never abandon their goodness.

Also said as

ગુજરાતી કહેવતસંગ્રહ (Gujarati Kahevat Sangrah) (1923) ગુજરાતી કહેવતસંગ્રહ (Gujarati Kahevat Sangrah) (1921) · read from the scan by machine — the Gujarati itself is unchecked · English is machine-made and nobody has checked it yet

Heard it differently, or know we've got the sense wrong? Tell us — that is exactly the kind of correction this needs.