A Brief History of Gilding Techniques
Gypsum USGS Eurico Zimbres FGEL/UERJ GNU by-nc: cobalt123 USGS by-nc-nd: skylarprimm.
Gypsum Wallboard Additives
Gypsum USGS Eurico Zimbres FGEL/UERJ GNU Attrib-NoCom: cobalt123 USGS Attrib-NoCom-NoDerivs: skylarprimm.
Biotite by-nc-sa: lore. This shows the three planes of biotite; notice the thin sheets. Bryce Canyon NPS Hopewell Culture National Historical Park/NPS.
