Boyd’s Bible Dictionary:

(white). Used by Hebrews from earliest times for money, vessels, and ornaments, but not in form of coins till after the captivity (Gen. 13:2; 24:53; 44:2; Job 28:1; Matt. 26:15; Acts 19:24). Silver supplied to Jerusalem from Arabia and Tarshish (2 Chron. 9:14,21).

Concise Bible Dictionary:

Silver Ruble
This was a source of wealth from early days. Abraham was rich in silver (Gen. 13:2); but with Solomon gold was so plentiful that silver was “nothing accounted of” (1 Kings 10:21). The silver and gold which he had amassed were, alas, afterward carried away to enrich their enemies because of the sins of Israel (2 Chron. 12:9). Silver was also the common specie of commerce, “pieces of silver” being weighed long before money was coined (Gen. 23:16). Silver was used for the sockets, hooks, etc., in the tabernacle, the money paid for the redemption of the Israelites being applied to this purpose (Ex. 30:11-16; Ex. 38:25-28). The house of God is founded on redemption (Ex. 36:24-36; Ex. 38:10-17).
Silver is found in the earth (Job 28:1), and before it can be compared to “the words of the Lord” it must be purified seven times (Psa. 12:6; Prov. 25:4).
THE SILVER CORD in Ecclesiastes 12:6 seems to refer to the thread of life, which is loosed, or removed, when death ensues.