Lithology 7. The naming of a lithology is based on the rock type. The three major rock types are sedimentary, igneous, metamorphic. Sedimentary rocks are further classified by whether they are siliciclastic or carbonate. Siliciclastic sedimentary rocks are then subcategorized based on their grain size distribution and the relative proportions of quartz, feldspar, and lithic (rock) fragments. Carbonate rocks are classified with the Dunham or Folk classification schemes according to the constituents of the carbonate rock. The name of an igneous rock requires information on crystal size and mineralogy. This classification can often be performed with a QAPF diagram. Metamorphic rock
Substance of very high concern occurred on 27 June 2018 to include a total 191 SVHC. The criteria are given in article 57 of the REACH Regulation. A substance "may" be proposed as an SVHC if it meets one or more of the following criteria: The "equivalent concern" criterion is significant because it is this classification which allows substances which are, for example, neurotoxic, endocrine-disrupting or otherwise present an unanticipated environmental health risk to be regulated under REACH. Simply because a substance meets one or more of the criteria does not necessarily mean that it will be proposed as an SVHC. Many such substances are