Search results
Results from the WOW.Com Content Network
Paraloid B-72 or B-72 is a thermoplastic resin that was created by Rohm and Haas for use as a surface coating and as a vehicle for flexographic ink.Subsequently, it has found popular use as an adhesive by conservator-restorers, specifically in the conservation and restoration of ceramic objects, glass objects, [1] the preparation of fossils, the hardening of piano hammers, [2] [3] and can also ...
Fossil preparation is a complex of tasks that can include excavating, revealing, conserving, and replicating the ancient remains and traces of organisms. It is an integral part of the science of paleontology, of museum exhibition, and the preservation of fossils held in the public trust.
Tree remains that have undergone petrifaction, as seen in Petrified Forest National Park. In geology, petrification (from Ancient Greek πέτρα (pétra) 'rock, stone') is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals.
Gypsum is a common mineral, with thick and extensive evaporite beds in association with sedimentary rocks. Deposits are known to occur in strata from as far back as the Archaean eon . [ 16 ] Gypsum is deposited from lake and sea water, as well as in hot springs , from volcanic vapors, and sulfate solutions in veins .
Hydraulic cements (e.g., Portland cement) set and become adhesive through a chemical reaction between the dry ingredients and water. The chemical reaction results in mineral hydrates that are not very water-soluble. This allows setting in wet conditions or under water and further protects the hardened material from chemical attack.
Stromatolites are a major constituent of the fossil record of the first forms of life on Earth. [24] They peaked about 1.25 billion years ago (Ga) [22] and subsequently declined in abundance and diversity, [25] so that by the start of the Cambrian they had fallen to 20% of their peak.
Minerals bond grains of sediment together by growing around them. This process is called cementation and is a part of the rock cycle. Cementation involves ions carried in groundwater chemically precipitating to form new crystalline material between sedimentary grains. The new pore-filling minerals form "bridges" between original sediment grains ...
Goethite (/ ˈ ɡ ɜːr t aɪ t /, [6] [7] US also / ˈ ɡ oʊ θ aɪ t / [8] [9]) is a mineral of the diaspore group, consisting of iron(III) oxide-hydroxide, specifically the α-polymorph. It is found in soil and other low-temperature environments such as sediment.