Database fields, all categories

Site identification
	`site`	The name or names of the mine, prospect or mineral occurrence as it is referred to in the literature. If more than one name has been used, the primary name is the one in most common usage and is listed first.
	`ARDF_num`	Unique label assigned to each site. First two letters comprise the quadrangle code, followed by a three digit number.
	`MRDS_num`	Unique identifier for the record as it appeared in the Mineral Resources Data System (MRDS).
Geographic location
	`district`	Name of the general area in which the site is located.
	`quad_250`	USGS topographic maps on which the site is located. The first two letters are a code for the 1:250,000-scale quadrangle.
	`quad_63360`	USGS topographic maps on which the site is located. Maps are identified in two parts, a two-letter code for the 1:250,000-scale quadrangle followed by the letter, hyphen, and number(s) used to designate the 1:63,360-scale map sheet. following USGS.
	`latitude`	Location of the site in decimal degrees. Some sites cover large areas and the location given is a point at the approximate center of the area.
	`longitude`	Location of the site in decimal degrees. Some sites cover large areas and the location given is a point at the approximate center of the area.
	`location`	A narrative description of the location of the site and its areal extent, which should also include information on the reliability of the location.
Site characteristics
	`ore`	A list of the minerals in the site, usually metallic, which are of potential economic value.
	`gangue`	A list of the non-economic minerals in the site that cannot be avoided in mining but are separated during concentration.
	`site_type`	The sites described in this database are separated into mines, prospects, and mineral occurrences. In general, mines have past production, prospects have had some development work, and mineral occurrences include unexplored or incompletely explored oc
	`status`	Inactive or active. An active designation indicates recent work at the time of record entry or update. The determination of this status is not to be construed to reflect the legal status of the site, but rather indicates the appearance of exploration
	`production`	Restricted to "yes", "no", or undetermined ("undet."). "Yes" may be qualified as small, medium, or large.
	`dep_model`	One or more named descriptive or genetic mineral deposit models listed in Cox and Singer (1986), Bliss (1992), or other indicated references. The models shown are those that appeared most appropriate to the compilers of the site record.
	`geol_desc`	Local geology and character of the deposit including, where possible, the host rock, structure of the host and mineralized system, mineralogical relations, and the shape and form of the deposit.
	`work_expl`	A description of the mining or exploration efforts to evaluate a mine or prospect. For mineral occurrences, this field would normally include the work done or the evidence to suggest mineral potential.
	`comments`	Pertinent information not appropriate for other fields in the description
	`reference`	List of known references that discuss the occurrence or are applicable to its description.
	`rept_names`	Names of people responsible for completion of the record.
	`rept_date`	Date of record entry or last update.
	`age`	The age of mineralization and an explanation of the evidence for the age, if warranted.
	`rept_aff`	Institutional affiliation of the reporter providing the information about the site.
	`model_code`	Unique identifier for the mineral deposit model, from Cox and Singer (1986) or Bliss (1992).
	`alteration`	Description of alteration of the deposit
	`prod_notes`	More extensive (and variable) information about production at the site, if known.
	`reserves`	Reserve figures and references to their source. This field may include estimates based on a variety of assumptions at various times; this can result in conflicting assessments of reserves. This field may also include resource estimates based on probab
	`prime_ref`	The best reference describing the occurrence, although it may be far from a complete description.
Commodities
	`comm_main`	Dominant elements or commodities of real or potential economic value in the site. For some deposits, the list of commodities is only a list of elements identified in a sample or samples and does not necessarily indicate the commodities that ultimatel
	`comm_other`	Other commodities present in minor amounts as determined by analysis or mineralogical determination. For some deposits, the list of commodities is only a list of elements identified in a sample or samples and does not necessarily indicate the commodities