The common radioactive elements—potassium, thorium, and uranium—are normally insignificant in [[reservoir fluids]], whereas they are important components of the rock system, especially of clay minerals. [[Basic open hole tools#Gamma ray|Gamma ray]] logs are therefore a good indicator of mineralogy.
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The common radioactive elements—potassium, thorium, and uranium—are normally insignificant in [[reservoir fluids]], whereas they are important components of the rock system, especially of clay minerals. [[Basic open hole tools#Gamma ray|Gamma ray]] logs are therefore a good indicator of [[mineralogy]].