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I am sorry to hear about this situation. In Texas, if the deed is silent on the mineral rights, they are assumed to be conveyed along with top soil. Many times the deed will mention both the top soil and mineral rights. However, not always. And again, the presumption is that BOTH are included unless the deed specifically leaves out one or the other or otherwise limits conveyance.
This means that unless the the deed specifically stated that mineral rights do NOT go to him at at the time of "he retained the 46 acres again in the final divorce, but did not stipulate the mineral rights," the mineral rights were retained with those 46 acres, and now belong to his estate.
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