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what type of stone is this?

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  • what type of stone is this?

        this is a blue,green stone from upstate ny.

  • #2
    Looks like a form of Chalcedony
    Chalcedony is not scientifically its own mineral species, but rather a form of Quartz in microcrystalline form. However, the name is an old name, and almost all mineral reference guides and collectors distinguish Chalcedony separately from Quartz. In the gem trade, the name Chalcedony usually describes only white or blue Chalcedony, to distinguish it from the multicolored banded variety Agate and other unique varieties of this mineral.
    Chalcedony is quite varied in its formation habits. It sometimes occurs in geodes, lining the cavity with mammilary blobs. Its Agate variety is also found in geodes, commonly lining the outer layer underneath the larger Quartz crystals. Chalcedony also forms pseudomorphs after organic material. A well-known example is petrified wood, in which the wood has been completely transformed into Chalcedony. In the Petrified Forest National Monument in Arizona, an entire forest was transformed into petrified wood. Remains of this ancient forest can be seen in the huge silicafied logs that are found in the area.
    Another well-known pseudomorph is Chalcedony after coral. In the Tampa Bay in Florida, coral has been chemically replaced by Chalcedony, and its original form is preserved. Another famous Chalcedony pseudomorph is Tiger's Eye. This popular variety has very unique optical properties in the form of a bronze sheen that is caused by the fibrous mineral Crocidolite that was chemically replaced into Chalcedony through pseudomorphism.
    Impurities are frequently present in Chalcedony. They may form a moss like growth in the mineral, forming what is known as Moss Agate. Another example is Dendritic Agate, a variety of Chalcedony containing manganese oxide impurities that form fabrications resembling trees. These forms of Agate are not true Agates, since they lack the banding.
    Varieties for Agate and Jasper are listed separately.
    Agate Jasper  -  Form of banded Jasper; a variety of both Agate and Jasper.
      Agate  -  Banded variety of Chalcedony.
      Aventurine  -  Opaque form of compact Quartz or Chalcedony containing small Mica, Hematite, or Goethite scales which cause a glistening effect. Aventurine is most often green but may also be other colors such as gray, orange, and brown. Although technically Aventurine is classified as rock due to its composition of several minerals, it most often is regarded as a variety of Quartz or Chalcedony.
      Binghamite  -  Chalcedony with dense, parallel inclusions of Goethite. Its color is a multicolored yellowish to reddish, and it exhibits chatoyancy. Binghamite was found in the Cuyuna Iron Range in Minnesota, and is used as a rare gemstone.
      Bloodstone  -  Dark green to greenish blue variety of Chalcedony speckled with red or brown spots.
    (May also refer to Hematite with red or brown spots.)
      Carnelian  -  Red to amber-red translucent variety of Chalcedony.
      Chert  -  Compact form of Chalcedony typically found as nodules in sedimentary rocks, usually with an off-white, gray, or cream color. Although technically Chert is classified as a rock due to its composition of other mineral impurities, it most often is regarded as a variety of Chalcedony.
    Chrysoprase  -  Apple green variety of Chalcedony.
      Fire Agate  -  Form of Agate, or more properly Chalcedony, that is iridescent with a play of colors or "fire" similar to that of Opal. The play of color is caused by inclusions of Goethite or Limonite.
      Flint  -  Massive, uniformly colored form of Chalcedony that is somewhat impure. Flint is well-known for its sharp edges and usage as tools such as arrowheads by the early Native Americans. Although technically Flint is classified as a rock due to its composition of other mineral impurities, it most often is regarded as a variety of Chalcedony.
      Hawk's Eye  -  Pseudomorph of compact Quartz after the fibrous mineral Crocidolite, with a chatoyant sheen, very similar to Tiger's Eye. It has a bluish-gray color, which differentiates it from Tiger's Eye which has a yellow-brown color.
      Holly Blue  -  Translucent, violet-blue variety of Chalcedony, often used as a gemstone. It is sometimes banded.
      Jasper  -  Opaque form of Chalcedony, most often used to describe brown, yellow, or reddish colors.
      Moss Agate  -  Chalcedony containing dense inclusions of green Hornblende that cause the pattern to resemble moss. Moss Agate is not true Agate as it lacks the banding patterns of Agate.
      Myrickite  -  Agate/Chalcedony or Opal with red bands or red spots of the mineral Cinnabar. It is named after Myrick Spring, San Bernardino Co., California.
    Onyx  -  Form of Chalcedony or Agate that has a black base and white banding or a white upper layer. May also refer to a solid black Chalcedony. Occasionally also refers to banded Travertine or Tufa in the mineral form of Calcite or Aragonite with black and white bands.
      Petrified Wood  -  Petrified Wood is wood that chemically replaced by a mineral substance. The replacement is usually Chalcedony, but Opal and a few other minerals are also known to replace the wood. When the wood becomes petrified, its original mold remains intact, but an entire new substance takes the place of what was once wood. When the mineral replacement of the wood is Chalcedony or Opal, the substance is also called "Silicafied Wood".
      Plasma  -  Dark green variety of Chalcedony. It often contains small white or yellow spots.
      Prase  -  Light to emerald green, transparent to translucent Quartz, with coloring caused from inclusions of green minerals, such as Actinolite, Hedenbergite, Chlorite, or Malachite.
      Sard  -  Brownish to brownish-red, transparent to translucent form of Chalcedony.
      Sardonyx  -  Form of Agate with parallel bands of brownish to red alternating with white or sometimes black bands.
    Tiger's Eye  -  Pseudomorph of compact Quartz after the fibrous mineral Crocidolite. Tiger's Eye is famous for its chatoyant effect.

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    • #3
      thank you for the info

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