### substance | mineral | ore:

Magnetite
* Some magnetite replaces feldspars along fractures.
* also is produced from peridotites and dunites by serpentinization
  - occurs as lamellar aggregates in calcite and in breccias from the Buckwheat Open Cut
* can have crystals.
* common mineral.
* defines a vertebrate magnetoreceptor.
* fills small channel cut in gabbroic cumulates.
* gives a black streak.
* is abundant along vein walls as is pyrite and some jade
  - also of economic importance
* is an important iron ore, along with hematite
  - ore of iron
  - source of iron ore and occurs in many igneous rocks
  - iron ore with structures that can carry a magnetic charge
* is an iron oxide, similar to iron rust
  - something like iron rust
  - common in basalt and gabbro the main rocks formed along the mid-ocean ridge
  - excellent source of paramagnetic energy for organic gardening
  - found both in sedimentary and igneous rocks
  - made by some magnetotactic bacteria on Earth
  - naturally magnetic
* is one of the magnetic minerals and pyrrhotite is the other
  - most common meteorwrongs
  - produced both biologically and inorganically on Earth
  - submetallic black with cubic crystal form and octahedral cleavage
* is the catalyst for the industrial synthesis of ammonia
  - most magnetic of all the naturally occurring minerals on Earth
  - raw material used for the production of iron and steel
  - very easy to identify
* major accessory mineral in veins
  - ore mineral of iron, and as mineral specimens
* mineral and one of the main iron ores.
* mineral that has a very high iron content
  - natural magnet
* occurs as euhedral crystals
  - inclusions in pyroxene grains
  - microlites, and microphenocryst magnetite is exceptional and destabilized
  - locally, with partial to total alteration to hematite
* preserves no strong crystallographic preferred orientation in any of the samples.
* progressively disappears in favor of pyrrhotite with increasing temperature.
* severe problem in new , hot water systems.
* very common and widely distributed accessory mineral in rocks of all kinds.
* well known ferrimagnetic material.

Metal ore
* Most metal ores require processing to produce one or more suitably pure products.
* found in the earth, like gold and silver, are minerals.

Siderite
* is iron ore
* occurs as oxidized masses and drusy xls.

Sludge
* Most sludge is landfilled or applied to land.
* are caked-on grease and oily dirt that build up on the bottom of the separator.
* consists of water and the solid matter removed from sewage during the treatment process.
* contains oil, grease, sand, and much, much more.
* is ore
  - precipitate
  - substances
* pumps During the solids digestion process, methane gas is produced by microbial action.

### substance | mineral | ore | sludge:

Secondary sludge
* are the extra microorganisms from the biological treatment processes.
* is more liquid than primary sludge.

### substance | mineral | ore | sludge:

Sewage sludge
* All sewage sludges contain the heavy metals copper, zinc, nickel, and lead.
* contains heavy metals, particularly cadmium.
* has nice nutrients
  - valuable agronomic properties in agriculture
* is an end product of the wastewater treatment process
  - organic slow release fertilizer
  - good for composting because it provides water, organic matter, and microorganisms
  - in fact an amalgamation of all the wastes of our society
  - produced in the huge quantities day after day, year after year
  - rich in nutrients and organic matter
  - solid, semi-solid, or liquid waste from a municipal wastewater treatment plant
* is the biological residual produced during the treatment of sewage wastewater
  - residue left after treatment at a sewage works
* means sludge from a facility treating wastewater from a sanitary sewer system.
* provides a major pathway by which drugs enter the environment.
* recycled product of municipal sewage treatment plants.