What is the difference between serpentine and serpentinite

In this chemical reaction, the water is converted to hydroxyl groups OH that are part of the serpentine minerals. Explore This Park. Info Alerts Maps Calendar Reserve. Alerts In Effect Dismiss. Dismiss View all alerts. Serpentinite FAQ. Serpentinite hand specimen Were does serpentinite form? Serpentinite is probably very widespread rock deep below, but not nearly as common in the upper parts of the crust.

Here it occurs mostly where ultramafic rocks occur ophiolite complexes. Serpentine minerals along with other green-colored alteration minerals talc and chlorite are still pretty widely distributed because olivine and pyroxenes are readily available in many places. Serpentinites has been important sources of asbestos, but nowadays the use of asbestos has diminished considerably because of health concerns.

The danger associated with asbestos comes mostly form amphibole asbestos minerals, but it is hopeless to assume that the fearmongering media would take the trouble and educate themselves and their readers about the different types of asbestos minerals.

So, we continue to see dangers in harmless amounts of chrysotile asbestos in floor tiles while we neglect or happily tolerate far more important health risks like fast food and lack of physical exercise which kills millions every year.

Serpentinite where the dominant serpentine mineral is fibrous chrysotile. The sample is from the Sayan Mountains in Siberia. Width of sample is 8 cm. Serpentinite green with white magnesite from Norway. Serpentine and magnesite may occur together if there were enough carbon dioxide available during the metamorphism to form magnesium carbonate magnesite.

Width of sample 24 cm. Serpentine-rich skarn sample with hedenbergite iron-rich Ca-clinopyroxene. Serpentine in skarn may form if the carbonate host rock is dolomite that provides lots of magnesium to form magnesium-rich silicates like serpentine minerals.

From Easton, Pennsylvania. Some varieties of serpentine have a fibrous habit. These fibers resist the transfer of heat, do not burn, and serve as excellent insulators. The serpentine mineral chrysotile is common, found in many parts of the world, is easily mined, and can be processed to recover the heat-resistant fibers.

The use of chrysotile and other serpentine minerals with an asbestiform habit as insulators has been widespread. They were widely available, effective in their applications and inexpensive to produce. By the middle of the 20th century, they could be found in most buildings and vehicles.

They were used to make wall and ceiling tiles, flooring, shingles, facing material, pipe insulation, stoves, paints, and many other common construction materials and appliances.

After they were discovered to be connected to lung and other cancers, their use was mostly discontinued, and a campaign to remove them from many of their uses began.

Removal programs have been ongoing for decades and are still being done today. It has been one of the most costly removal programs in history. Serpentine Cabochons: Three interesting cabochons cut from various types of serpentine. This is only a small example of the infinite diversity of serpentine gem materials. Lime Green Serpentine: Rare specimens of serpentine have a wonderful green color, clarity, and translucence.

These specimens have the appearance of nice jade and are sometimes confused with it in retail products. Attractive serpentine can be cut into a wide variety of gemstones. It is most often cut into cabochons and beads. They usually display a range of green, yellow, and black colors and often have magnetite, chromite, or other minerals as interesting inclusions. The lower left side of the green and black cabochon in the center of the photo on this page contains enough included magnetite that the cab can be moved with a small hand magnet.

Gemstone-quality serpentine is easy to polish, and beautiful finishes are possible. However, it usually polishes to a waxy luster rather than the brilliant glassy luster of much harder materials such as agate, jasper, and faceted stones.

Rockhounds who polish their first piece of serpentine and know this have their expectations calibrated in advance. The waxy luster is a beautiful and common characteristic of the material. It does not reflect the skill of the operator. Extra polishing time and effort will still produce a waxy luster. Serpentine has some durability concerns.

It has a hardness that ranges from 3 to 6 on the Mohs scale. Three is far too soft for anything but the most gently-worn jewelry such as earrings, brooches, or pendants. A Mohs hardness of six is not hard enough for confident use in a ring or bracelet. Much of the information presented in this post comes from the educating and advocacy about this issue by geoscience educator Garry Hayes at his blog Geotripper , Bay Area science writer Andrew Alden at geology.

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