Diatomite is a generally light-colored sedimentary rock that is composed mostly of the siliceous skeletons of diatoms. It is an extremely porous rock with a fine particle size and a low specific gravity. These properties make it useful as a filter media, especially for beer and wine. It is also used as an absorbent, and as a lightweight filler for paint and plastics. When diatomite is crushed into a very fine powder, it is called diatomaceous earth.
Diatoms are members of a large, diverse group of algae that drift in the waters of both oceans and lakes. A few types of diatoms live on the bottom of these water bodies and in soils. Most diatoms are microscopic, although a few species are up to two (2) mm in length. As a group, diatoms are unique because they are single-celled organisms that produce an external cell wall composed of silica, called a frustule. These frustules are very thin and have a delicate structure.
Most diatoms are photosynthetic and live in water less than thirty (30) feet deep, where sunlight can penetrate. Diatoms are prolific and are responsible for producing nearly half of the organic mass in the world’s oceans. Their abundance and tiny size places them at the base of the marine food chain. We have discussed the strength and Fibonacci ordering of diatoms before here at PEOTS.
After diatoms die ("die, atoms, die!"-- sorry, I couldn't resist) their siliceous frustules sink. In some areas, the frustules are not incorporated into the bottom sediment because they dissolve as they sink or dissolve while on the sediment surface. If the sediment is composed of over 30% diatom frustules by weight, it is called diatomaceous ooze or siliceous ooze.
Of course, all this ooze discussion leads to a talk of diatomaceous ooze filtering your booze. Freshwater ooze or earth must be used unless you like your booze salty (yuck for me!). Diatomite from saltwater sources can contain salts that can produce objectionable or toxic effects. Although some beer crafters are, indeed, using salt in the brewing process. Enjoy the beer, skip the pretzels? Have a little diatomaceous ooze with your booze? Woe is mead?
The four main uses of diatomite in the United States during 2019 were filtration (50%), light aggregate (30%), fillers (15%), and absorbents (5%).
Diatomaceous earth is used as a lightweight, inert filler in some manufactured products. It is added to paint as a whitening agent and extender. Diatomite is added to plastics as a lightweight filler.
If dry diatomaceous earth is placed on a liquid spill, it can absorb and hold an amount of liquid equivalent to its own weight. This absorption facilitates containment, cleanup, and removal. Capillary action of liquids into diatomaceous earth is enhanced by its small particle size, high surface area, and its high porosity.
These same properties make diatomaceous earth able to absorb skin oils when used in cosmetics and facial masks. Diatomaceous earth is an absorbent ingredient of some kitty litters. It is also used as a soil treatment to absorb and hold water.
Diatomaceous earth is used as a mild abrasive in some toothpastes, facial scrubs, and metal polishes. Its silica particles are small, friable, have a high surface area, and are angular in shape. These are properties that help it perform well as a mild abrasive.
Diatomaceous earth is used as a growing medium in hydroponic gardens. It is inert, holds water, and has a porosity that allows the soil to breathe. To help grain and other seeds from sticking together and remain dry, they are dusted with diatomaceous earth.
The cost of diatomite depends on its quality, how it will be used, and the preparation effort that has been invested by the supplier. The cost of diatomite straight from the mine without processing for use in concrete starts at about $7/ton. Diatomite from high-grade deposits that has been crushed, sized, and sieved for use in cosmetics, art supplies, & DNA extraction markets can cost more than $400/ton.
The extraordinary intricacy of diatoms in Scanning Electron Micrographs shown throughout this post is astounding. Do you have a favorite?Hoping you are all well in this weirdest of times,P.S. Begone, M a r c h, oh longest of months this year.
I am fascinated by these redheaded pine sawflies (Neodiprion lecontei) on my geology professors' Mugo Pine (Pinus Mugo):
The sawfly was not a major pest problem in Mugo and other pines in the U.S. until the planting of large pine plantations in the 1930's.
The sawflies resemble caterpillars but are actually members of the wasp/bee family, not the butterfly/moth family. Caterpillars have up to 5 pairs of abdominal prolegs. Sawfly larvae have six or more pairs of abdominal prolegs:
Another notable difference, though it requires a much closer look (oh, yeah!), is that caterpillars have tiny hooks called crochets, on the ends of their prolegs. Sawflies don't. Here are the crochets on caterpillars (C on C as a way to remember the "cats" [entomologists' affectionate pet name for caterpillars] differentiation from sawflies):
And the Scanning Electron Microscope version of the crochets:
The common name of sawfly comes from the saw-like appearance of the ovipositor, or egg depositor, which the females use to cut into the plants where they lay their eggs.
The insecticides that are used on the caterpillar family do not work on sawflies. [And, of course, many caterpillars transform into much-needed and wanted butterflies.]There are some wasp/sawfly insecticides that are somewhat effective, including organic diatomaceous earth (remember the diatoms from our Scanning Electron Microscope {SEM } discussion earlier?):
However, one of the best ways to get rid of the sawfly larvae is to simply pull them off the Mugo pine trees. Any volunteers to get in there, count legs, and pull off the large clumps of sawflies? If so, they are in Northampton, Massachusetts, waiting for you. {Eric Carle used to be there, too, for over 30 years, though he recently moved southward to North Carolina and Florida.}
Wonder if Eric Carle ever counted pro-legs on caterpillars. . .
Any good caterpillar or sawfly tales? Might we count on you?
Steph
Here is an image from the August 4, 2015, Las Animas River after a 3,000,000+* gallon spill from the Gold King Mine in southwest Colorado (see link to article in 8/7/15 comment):
Indeed, next week's Partial Ellipsis will look at the Animas River Spill in Colorado. Please look there for a discussion of the Gold King Mine. I am cleaning up some of the graphs, have some new local photos to share, etc.
*Updated from the original EPA estimate of 1,000,000 gallons.
