For what it's worth, one or two 4-packs of Duracel D batteries and a sock make for a fantastic offensive weapon. None of which is restricted or really all that suspicious.

The day TSA can interdict everything that *could* be used as a weapon will be the day they send us on airplanes empty-handed and in our underwear.

However, since they continue to "operate with an abundance of caution" I expect that your success rates with large mineral samples will not be 100%. You fortunately happened upon a not-quite-useless clerk.