THE
MINERAL ANALCIME
- Chemistry: NaAlSi2O6-H2O, Hydrated Sodium Aluminum Silicate
- Class: Silicates
- Subclass: Tectosilicates
- Group: Zeolites
- Uses: mineral specimen and chemical filter.
Specimens
Analcime is a popular and interesting mineral. It is sometimes known
as analcite, although analcime is preferred. It is one of the few minerals
that characteristically forms its own unique crystal. Well, not quite its
own unique crystal, but pretty close. It forms the isometric
Distinguishing analcime from the garnets and leucite is relatively easy in some cases. The garnets are much harder and usually deeply colored. Leucite has a much lower density and usually has a dull luster. Also leucite is typically embedded in host rock where as analcime, when displaying good crystals and not massive or granular, is loose or attacted to other minerals in volcanic cavities.
Analcime, AlSi2O6-H2O is actually distantly related to leucite, KAlSi2O6. Leucite is a member of the feldspathoid group of minerals. Minerals whose chemistries are close to that of the alkali feldspars but are poor in silica (SiO2) content, are called feldspathoids. Feldspathoids are commonly found in silica-poor igneous rocks, where analcime is sometimes present as well. Analcime is sometimes placed in the feldspathoid group since its chemistry and occassional occurrences are similar.
Analcime's structure however has a typical zeolite openness about it that allows large ions and molecules to reside and actually move around inside the overall framework. The structure contains large open channels that allow water and large ions to travel into and out of the crystal structure. The size of these channels controls the size of the molecules or ions, and therefore a zeolite like analcime can act as a chemical sieve.
PHYSICAL CHARACTERISTICS:
- Color is clear, white or gray, with greenish, yellowish and reddish tints possible.
- Luster is vitreous.
- Transparency: crystals are transparent to translucent.
- Crystal System is isometric; 4/m bar 3 2/m
- Crystal Habits include the characteristic trapezohedron as well as the rare cube modified by trapezohedral faces. Also granular and massive.
- Cleavage is absent.
- Fracture is uneven.
- Hardness is 5 - 5.5.
- Specific Gravity is approximately 3.2 (average)
- Streak is white.
- Associated Minerals are quartz, calcite, serandite, apophyllite, natrolite, stilbite, heulandite and other zeolites.
- Notable Occurrences include Mont St. Hilaire, Quebec; Iceland; several localities in Oregon, Colorado and New Jersey, USA; Nova Scotia and Switzerland.
- Best Field Indicators are crystal habit, density, low hardness, luster and associations.
 Amethyst Galleries' Mineral Gallery MINERALS |
ANALCIME specimen ana-1
$ 30.00
$ 30.00
Dims: 1-3/4" x 1-5/8" x 1-1/8"
Wt: 2.1 oz
Tunguska River, Krasnojarsku Region, Russia
A classic specimen, this tiny piece of the Russian homeland is in the form of a partial(4 complete faces, 8 incomplete) trapezohedron that would likely have exceeded 2" in diameter if it had been complete. Widespread internal fracturing seems to give the crystal most of its white color, and there are 2 smaller, poorly formed analcime crystals on the matrix that covers the incomplete portion of the large crystal. It has clean, if not shiny, faces that don't easily show their definition through digital video capture.
ana-1 ($ 30.00)
Tunguska River, Krasnojarsku Region, Russia
ANALCIME specimen ana-2
$ 110.00
$ 110.00
Dims: 7-3/8" x 4" x 2-1/2"
Wt: 2 lbs., 2.5 oz
Poudrette Quarry, Mt. Ste. Hilaire, Quebec, Canada
Are you looking for a BIG specimen of Analcime? Here's one! It has several white crystals on it, measuring up to 2 inches in diameter. All of the crystals rest on a base that seems to be made up of nepheline that is infested with hornblende, and there are small amounts of biotite present. A few of the crystals are lightly damaged, one heavily so, but all the faces and edges on each dodecahedral crystal are clean and show a surprisingly good luster. This specimen has what I call "heft".
ana-2 ($110.00)
Poudrette Quarry, Mt. Ste. Hilaire, Quebec, Canada
ANALCIME specimen ana-3
$ 45.00
$ 45.00
Dims: 1.8" x 1.5" x 1.3" (4.6 x 3.8 x 3.3 cm)
Wt: 27.9 g
Mt. Ste. Hilaire, Quebec, Canada
This small hand specimen consists of at least 10 milky-white Analcime crystals that rest on a crystalline albite matrix. These crystals reach diameters of 0.4" (9 mm) and are in excellent condition, showing almost no visible damage. The growth of one of these crystals appears to have been interrupted, so that is is incomplete; however, the others have exceptional trapezohedral form, with well-defined edges and clean faces that possess a pearly luster. The crystals are translucent in bright light and are partly intergrown with each other and the gray, tabular albite that forms their base. Among the Analcimes and albites are many small, thin needles of aegirine. They appear to have good form and are mostly intact. They are visible primarily due to their black coloration and brigt vitreous luster. The specimen is affixed to a small, square acrylic stand with a hot glue.
ana-3 ($ 45.00)
Mt. Ste. Hilaire, Quebec, Canada
ANALCIME specimen ana-4
$ 60.00
$ 60.00
Dims: 1.3 x 1.2 x 1.1" (3.3 x 3.0 x 2.8 cm)
Wt: 16.1 g w/ base
Mount Sainte Hilaire, Quebec, Canada
This small thumbnail specimen consists of a single trapezohedral Analcime crystal that is impaled by several black aegirines. The crystal is in excellent condition, showing no human-induced damage, and has excellent form, with well-defined edges and clean faces that show a waxy luster. There is a small depression in one area where a smaller crystal was intergrown, but has since been removed. It has the standard milky-white coloration of Analcime and is translucent only around its edges. Portions of the crystal's surface appear to be stained gray, likely due to the inclusion of tiny crystals or pieces of crystals of aegirine. The larger aegirines that run through the Analcime show good crystal form, but are all damaged and incomplete. The largest of these measures 0.9" (2.3 cm) long and runs tangent to the Analcime crystal. It is also the point where the specimen is glued onto a square acrylic base, and would probably break if the specimen were separated.
ana-4 ($ 60.00)
Mount Sainte Hilaire, Quebec, Canada
ANALCIME specimen ana-5
$ 30.00
$ 30.00
Dims: 0.7 x 0.7 x 07" (1.8 x 1.8 x 1.8 cm)
Wt: 8.5 g w/ base
Mount Sainte Hilaire, Quebec, Canada
This small thumbnail specien consists of a single trapezohedral Analcime crystal. It does show some damage, but is generally in good condition. Though it is not quite complete, the crystal's form is excellent; it has well-defined edges and clean faces that possess a bright pearly luster. It has the standard white coloration and is completely opaque. Its form is incomplete where the crystal intersects with the small amount of host rock that is present. It is at this host rock that the specimen is hot-glued onto a small square acrylic base.
ana-5 ($ 30.00)
Mount Sainte Hilaire, Quebec, Canada
ANALCIME specimen ana-6
$ 32.00
$ 32.00
Dims: 2.2 x 2.0 x 1.2" (5.6 x 5.1 x 3.0 cm)
Wt: 1.39 oz. (39.6 g)
Mount Saint Hilaire, Quebec, Canada
At least 20 distinct Analcime crystals are intergrown to form this small hand specimen. They range in diameter from 1 or 2 mm to 0.7" (1.8 cm) and are generally in fair condition, as several show obvious damage. Their trapezohedral form is very good, with relatively well-defined edges and clean faces that possess a surprisingly dull waxy-to-matte luster. Oddly, all of the damaged crystals show hollow spaces and/or a porous, sponge-like texture within- their surfaces are merely thin shells! All have the classic milky-white coloration of this mineral and are opaque. There is no host rock present.
ana-6 ($ 32.00)
Mount Saint Hilaire, Quebec, Canada
ANALCIME specimen ana-7
$ 68.00
$ 68.00
Dims: 4.8 x 3.2 x 2.5" (12.2 x 8.1 x 6.4 cm)
Wt: 1 lb., 0.9 oz. (480.0 g)
Mount Saint Hilaire, Quebec, Canada
About 20 Analcime crystals rest on the pale gray host rock of this large specimen. These crystals range in diameter from less than 0.1" (3 mm) to nearly 1.5" (3.6 cm) and are generally in very good condition, as damage is minor and sparse. Their form is moderately fair, as almost all of these crystals were intergrown with crystals that have since been separated from the piece, leaving geometric depressions. Those edges and faces that are intact are respectively well-defined and clean and possess a dull waxy luster. They have the standard milky-white coloration, though they do show some rust-staining, and are opaque. The gray host rock is heavily pitted and contains many thin, needle-like crystals and several tiny sphenes.
ana-7 ($ 68.00)
Mount Saint Hilaire, Quebec, Canada
ANALCIME specimen ana-8
$ 32.00
$ 32.00
Dims: 1.4 x 1.3 x 1.0" (3.6 x 3.3 x 2.5 cm)
Wt: 1.04 oz. (29.6 g)
Mount Saint Hilaire, Quebec, Canada
A single Analcime crystal comprises this specimen. It is not complete, having intersected a schorl tourmaline crystal during its growth. It is in good condition, showing some noticeable human-induced damage. Its trapezohedral form is very good where intact, sporting well-defined edges and clean faces that possess a pearly luster. It has the standard milky-white coloration and is essentially opaque, though some of its edges are dimly translucent. The only other material present is the schorl, which has a very unusual shape, but is in surprisingly good condition. It would seem that the analcime broke off of the schorl, which was acting as a "stem", connecting it to the base rock. All breakage surfaces on the schorl are partially-healed.
ana-8 ($ 32.00)
Mount Saint Hilaire, Quebec, Canada
ANALCIME specimen ana-9
$ 55.00
$ 55.00
Dims: 1.2 x 1.2 x 1.2" (3.0 x 3.0 x 3.0 cm)
Wt: 23.1 g w/ base
Mount Saint Hilaire, Quebec, Canada
This lovely piece consists of a three heavily-intergrown Analcime crystals. Two of these crystals are much smaller than and heavily intergrown with the third, larger crystal, and are barely visible. The larger crystal measures 1.1" (2.7 cm) in diameter and is in excellent condition, showing no appreciable damage. Its trapezohedral form is likewise excellent, and its white color and pearly luster are standard for the species. Several pale gray bladed crystals accompany it. Their form makes me think of feldspar, and they are likely orthoclase. The piece is hot-glued onto a square acrylic base.
ana-9 ($ 55.00)
Mount Saint Hilaire, Quebec, Canada
ANALCIME specimen ana-11
$ 25.00
$ 25.00
Dims: 0.9 x 0.7 x 0.7" (2.2 x 1.9 x 1.8 cm)
Wt: 11 g w/ base
Mount Saint Hilaire, Quebec, Canada
Three partly-intergrown Analcimes make up the bulk of this thumbnail piece. Only one of these crystals is over 50% complete- actually, it is very nearly complete and measures about 0.8" (2.0 cm) in diameter. It is in excellent condition and shows equally excellent trapezohedral form. Its milky-white color and pearly-to-vitreous luster are standard for the specie, and it is translucent but nearly opaque. A few partial aegirine crystals extend from the piece, which is hot-glued to a small acrylic base.
ana-11 ($ 25.00)
Mount Saint Hilaire, Quebec, Canada
ANALCIME specimen ana-10
$ 30.00
$ 30.00
Dims: 1.1 x 0.9 x 0.8" (2.7 x 2.3 x 2.0 cm)
Wt: 12 g w/ base
Mount Saint Hilaire, Quebec, Canada
A single Analcime crystal permeated by several aegirines makes up this thumbnail piece. Though its trapezohedral form is somewhat warped in one area, it is in excellent condition and has otherwise good form. Its milky-white color and pearly-to-waxy luster is standard for its specie, and it is translucent in bright light. None of the accompanying aegirines are complete, and one serves as a "stem"- it is hot-glued at to the attached acrylic base at its end.
ana-10 ($ 30.00)
Mount Saint Hilaire, Quebec, Canada
ANALCIME specimen ana-12
$ 29.00
$ 29.00
Dims: 1.4 x 0.9 x 0.8" (3.6 x 2.3 x 2.0 cm)
Wt: 12 g
Mount Saint Hilaire, Quebec, Canada
This thumbnail piece consists of two partial Analcimes that are partly intergrown. The larger of the two crystals is more complete than the other, but both are in excellent condition, as their lack of completeness is based on intersection by minerals no longer present, as opposed to damage. Both have excellent trapezohedral form and the classic white color, pearly-to-waxy luster and milky opacity of the specie. A few broken aegirine blades intersect them, but there is no host rock present.
ana-12 ($ 29.00)
Mount Saint Hilaire, Quebec, Canada
ANALCIME specimen ana-13
$ 25.00
$ 25.00
Dims:1.3x0.8x0.5" (3.3x2.0x1.3 cm)
Wt: 0.2oz. (7g)
Mt St Hilaire, Quebec, Canada
This is an excellent cluster of analcime trapezohedrons from a classic local-Mt St hilaire. Three needles of aegirine pierce this specimen, although only one is visible on the display side. There is only two small points of contact on this specimen-very nearly a floater. There is a small amount of damage to one of the crystals at a contact point. The crystals show a high level of translucency.
ana-13 ($ 25.00)
Mt St Hilaire, Quebec, Canada
ANALCIME specimen ana-14
$ 38.00
$ 38.00
Dims: 0.8x0.6x1.7" (2.0x1.6x4.2 cm)
Wt: 0.3 oz. (7.3g)
Mt. St. Hilaire, Quebec, Canada
This interesting thumbnail specimen features several large analcime crystals perched upon a tall slender aegirine crystal. The analcime crystals have the proper form - they almost look like white garnets. There are several more aegirine needles on the back, and there is another white mineral (tiny white blades) on the top of the specimen, I have not identified it.
ana-14 ($ 38.00)
Mt. St. Hilaire, Quebec, Canada