if not a maker's mark, and the metal is gold colored, PAL mark on gold colored metal could indicate the metal is Palladium-gold. Palladium itself has been used in jewelry since 1939 more as an alternative to white gold. White gold is an alloy of gold decolourised by the addition of palladium. Palladium is also used with gold, silver and other metals as a "stiffener".
Palladium-gold is a more expensive alloy than nickel-gold but will seldom cause allergic reactions (though certain cross-allergies with nickel may occur).
