460 (page 7 of their guide)
DEFINITION OF ARTICLES OF UNUSUAL VALUE, WHICH ARE NOT ACCEPTED
BY UPS FOR TRANSPORTATION
Shippers are prohibited from shipping articles of unusual value via UPS. Articles of unusual value shall be deemed to include, but are not limited to:
(1) Coins (except pennies and nickels, and except proof and mint sets of United States coins tendered by United States mints of a face value not to exceed $2.41), currency, postage stamps, negotiable instruments (except checks), money orders, unset precious stones, and industrial diamonds.
(2) Any article which contains more than fifty percent by weight of gold, silver, or platinum or any combination thereof in raw form, bullion, balls, bars, grains, strip, sheet, wire, chain, ingots and the scrap of these metals.
(3) Any package having a value of more than $50,000. UPS will not be liable for any loss of, or damage to, articles of unusual value.

510
FILING OF CLAIMS
All claims for loss or damage to property transported or accepted for transportation must: (1) be in writing and must include reference to the source document or pickup record number and date of shipment or copies of other documents sufficient to identify the shipment involved, and the insured value; (2) assert the liability of UPS, and/or any applicable insurance company, for alleged loss or damage; (3) make claim for payment of a specified or determinable amount of money; and (4) be accompanied by a copy of the original invoice or, if no invoice was issued, other proof, certified to in writing, as to the actual cost or replacement cost of the property, or extent of the damage to the property.
No claims will be voluntarily paid unless filed in writing by or on behalf of the shipper in accordance with these provisions. Where the shipper purchased excess value insurance by inserting an amount greater than $100 in the insured value field of the UPS automated shipping system or source document used by the shipper, and where the shipper has paid the charge for such insurance, the insured value claim will be adjusted on behalf of the insurance company.

LIMITATIONS OF LIABILITY
Whenever property is damaged or lost by UPS in the course of transportation, and a valid claim has been filed in accordance with Items 510, 520, and 525, UPS will pay, at its option, the lowest of the following, not to exceed $100: (1) for the damaged or lost goods; (2) for the actual cost or replacement cost of the property;
or (3) for the cost of repairing the damaged property. When UPS pays the actual cost of the property, title to the property shall thereupon pass to UPS; otherwise, the damaged property shall be returned to the shipper.