Hi Rodear & welcome to T-net , My first thought was heating stone , ..I dont see any polish on the ends [bits] if an edged tool ? So ,is the material somewhat grainy with a bit/lots of mica in it . the best material for these heating stones have alot of biotites [iron rich mica] in them ,. and its the unique property of these random interlocking plates that hold these heating stones together during extream heating & cooling ......anyway...
well, heres a pic of some so. cali heating stones ,..some are drilled most are not . Yours "looks" similar ,..except for those tally marks

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And heres a pic of a piece of hemitite thats been cane drilled ,..looks as if a "modern" core bit was used doesn't it ?
Anyway ,..Maybe.....Blindpig