Should the questioner retrieve the 5000 Syrian Pounds, or should she take the value of the gold earrings her friend left as collateral, taking into account the difference in gold prices between the time of the debt and now?

The mortgaged item belongs to the mortgagor, who benefits from its gains and bears its losses, according to the consensus of scholars.

Therefore, the mentioned earrings belong to your friend, and you have no claim to them. What she owes you is only the money she borrowed from you, which is 5000 Lira.