There are reports of even "experienced" mushroom pickers making mistakes and dying from eating shrooms they thought were perfectly fine. It's takes years to learn the thousands of varieties. I was always taught the "blueing" of the shrooms when handled indicated the presence of psylicibin (sp?) but better safe than dead! But it's a safe bet that unless you live on or near a farm with cows, they aren't magic mushrooms. In the wild they normally grow on cow patty's (shit), although I've seen them on other medium too.