Beekite is a distinctive form of chalcedony usually associated with silica replacing carbonate minerals in fossils (e.g., the top part of the coral illustrated).[1]
Beekite, recognised as small, concentric rings (cylinders, ellipsoids, or spheres in 3D) of microcrystalline quartz, is recorded as first brought to geologists’ attention by Henry Beeke, probably from studies around Torbay.[2] Early studies were reported by Thomas McKenny Hughes, in Devon,[3] and R. Etheridge in Australia.[4]
A study of the taphonomy of silicified fossils (especially brachiopods) in Devon concluded beekite resulted from the aerobic decomposition of organic matter in an environment with a limited supply of silica during early diagenesis.[5] Elsewhere, beekite has been compared to silcrete, indicating a break in sedimentation, where it occurs as encrustations on clasts of carbonate rock in the Palaeocenealluvial fan deposits of central Anatolia.[6]
^H.K. Holdaway & C.J. Clayton (1982). "Preservation of shell microstructure in silicified brachiopods from the Upper Cretaceous Wilmington Sands of Devon". Geological Magazine. 119: 371–382. doi:10.1017/s0016756800026285.
^Kazanci Nizamettin (1993). "The occurrence and significance of beekite in Palaeocene alluvial-fan deposits in central Anatolia, Turkey". Terra Nova. 5: 36–39. doi:10.1111/j.1365-3121.1993.tb00224.x.