California Code, Civil Code - CIV § 2200

A common carrier of gold, silver, platina, or precious stones, or of imitations thereof, in a manufactured or unmanufactured state;  of timepieces of any description;  of negotiable paper or other valuable writings;  of pictures, glass, or chinaware;  of statuary, silk, or laces;  or of plated ware of any kind, is not liable for more than fifty dollars upon the loss or injury of any one package of such articles, unless he has notice, upon his receipt thereof, by mark upon the package or otherwise, of the nature of the freight;  nor is such carrier liable upon any package carried for more than the value of the articles named in the receipt or the bill of lading.