Improperly Mixed Alloy Mint Error.. Also know as a Woodie Here is some information - http://www.error-ref.com/improper-alloy-mix/ Quote - "A poorly mixed alloy can result in alternating light and dark streaks. This is often referred to as a “wood grain” pattern, and the coins themselves as “woodies”." Closed quote There are several threads on CoinTalk on these.. Do a search using the words -Improperly Mixed Alloy
