# properties.id.description
The medium code is the 3-character alpha code that identifies the material type and quality-assurance type of the sample. The first character of the code is the \"super\" medium, which describes the primary matrix of the sample. The second character is the sub-medium, which characterizes the sample type as a unique entity within the \"super\" medium category. The third character is used to designate whether a sample is an environmental or QC sample. A blank in position three denotes an environmental sample; a \"Q\" in position three denotes a QC sample.

# properties.medium_name.description
The medium name is a short identifying appellation that explains the associated medium code. See qwmed for examples of codes, names, and descriptions.

# properties.medium_description.description
The medium description is a short string of words that explains the associated medium code. See qwmed for examples of codes, names, and descriptions.

# properties.legacy_medium_code.description
Historical 1-char medium code that corresponds to the 3-char code.