Andrew – Research Credit

This guide covers the best rockhounding sites in Arkansas, the eight rocks and minerals you are most likely to find, and the land rules that …

Opal is hydrated silica (SiO₂·nH₂O), a mineraloid with no crystal structure that can hold up to about 20% water. It rates 5.5–6 on the Mohs …

This guide covers the best places to rockhound in Michigan, from the Petoskey stone beaches of the Lower Peninsula to the agate shores and copper …

Petrified wood is a fossil in which the original wood has been replaced by minerals, mostly quartz, while keeping its rings and grain. Silica-rich pieces …

A geode is a hollow, roughly spherical rock – usually formed from a gas bubble in volcanic rock or a cavity in sedimentary limestone – …

This guide covers the best rockhounding sites in Colorado, the 21 rocks and minerals you are most likely to find, and the land rules that …