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BENITOITE |
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- Chemistry: BaTiSi3O9, Barium Titanium Silicate.
- Class: Silicates
- Subclass: Cyclosilicates
- Uses: As a gemstone and as a mineral specimen
Specimens
Benitoite is associated with a few rare minerals such as black-red neptunite, snow white natrolite and brown-yellow joaquinite. The only source of this rare combination occurs at San Benito, California. They are formed in fractures of a serpentine rock from hydrothermal solutions. These solutions contained a number of unusual elements such as barium, titanium, fluorine, iron, cesium, niobium, manganese and lithium in relatively high concentrations. How such a solution occurred and what other conditions caused the crystallization of these rare minerals is still not well understood. The rare clusters of blue benitoite and black neptunite on top of a crust of white natrolite produces a truly fantastic and a one of a kind mineral combination that is a must have for a serious mineral collector.
PHYSICAL CHARACTERISTICS:
- Color is typically blue, but also colorless and yellowish.
- Luster is vitreous.
- Transparency: Crystals are transparent to translucent.
- Crystal System is hexagonal; bar 6 m 2
- Crystal Habits include the flattened six faced dipyramid that has a distinct triangle shape often modified by minor faces. Also found as small grains.
- Cleavage is absent.
- Fracture is irregular.
- Hardness is 6 - 6.5
- Specific Gravity is approximately 3.6 (above average)
- Streak is white.
- Other Characteristics: Nearly all specimens fluoresce blue under UV light.
- Associated Minerals include serpentine,
neptunite,
natrolite,
joaquinite,
sanbornite,
taramellite , albite andfresnoite . - Notable Occurrences include only the mines of San Benito County, California, USA for good excellent crystals. SW Texas produces tiny grains in eocene sands as well as some other California localities.
- Best Field Indicators are crystal habit, fluorescence, color, associations and locality.
 Amethyst Galleries' Mineral Gallery MINERALS |
BENITOITE specimen ben-1
$ 45.00
$ 45.00
Dims: 1" x 5/8" x 3/8"
Wt: 8 g w/ base
San Benito County, California, U.S.A.
Even though this Benitoite specimen is very small, it is still a spectacular little piece of the Earth. The crystals themselves do not measure over 1/2 inch long. However, given that Benitoite comes from only one locality, one can consider this specimen to be a impressive one. The Benitoite crystals are moderate to deep blue in color, and occur in a form that is shaped like a kite with three crystals of Neptunite (reaching 1/4 inch in length) in a Natrolite matrix. This mineral is difficult to find, and unless a new source is located, supplies of it will be dwindling on the collector's and jeweler's markets.
ben-1 ($ 45.00)
San Benito County, California, U.S.A.
BENITOITE specimen ben-2
$ 140.00
$ 140.00
Dims: 1" x 5/8" x 3/8"
Wt: 9.6 g
San Benito County, California, U.S.A.
This particular specimen is packed with 18 or 19 triangular Benitoite crystals. They all have good form, if incomplete, and a medium gray-blue color. They are translucent to transparent, and some, including the largest crystal on the specimen(1/4" long per side), have inclusions. Though the image doesn't do them justice, they all glow very brightly under shortwave UV radiation. There are two tiny neptunite crystals hitching a ride, too; one of them is double-terminated, and actually may be made up of two very thin double-terminated crystals that have grown side by side, and parallel to each other-they look like mirror-twins!
ben-2 ($140.00)
San Benito County, California, U.S.A.
BENITOITE specimen ben-3
$ 105.00
$ 105.00
Dims: 2-1/2" x 1-3/8" x 3/4"
Wt: 23.6 g
Gem Mine, San Benito County, California, U.S.A.
Dozens of tiny(max. length on a side- 1/8"), triangular and hexagonal Benitoite crystals lie on a blue-gray matrix that is partially crusted with natrolite. The crystals all have good form, though several are incomplete and some are intergrown with others of their kind. Their color is consistently a medium grayish-blue, and they are semi-transparent. Their crystal faces are all clean, and show a vitreous luster. Though our image does not show it well, they all glow a bright blue-white under shortwave UV radiation.
ben-3 ($105.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-4
$ 175.00
$ 175.00
Dims: 1.5" x 0.8" x 0.6" (3.8 x 2.0 x 1.5 cm)
Wt: 8.6 g
Dallas Gem Mine, San Benito County, California, U.S.A.
Though there are less than 10 Benitoite crystals on this specimen, and less than half of those are complete, those that are intact are excellent in size and physical condition. Two of the crystals in particular are the most noticeable. Each has dimensions equaling or exceeding 0.3 x 0.2 x 0.2" (0.8 x 0.5 x 0.5 cm) and shows no visible human-induced damage. Their nearly hexagonal tabular shape is excellent, with well-defined edges and smooth, flat faces that have an unusually dull, matte luster, possibly due to a very thin coating of some other mineral. All have a deep, sapphire-blue coloration and appear to be quite transparent, though they show considerable internal fracturing. All are partially enveloped by a crust of natrolite that seems to be covering a few more crystals. I don't know how to remove this crust, but if one did, there may be at least one or two more crystals exposed.
ben-4 ($175.00)
Dallas Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-5$ 310.00
Dims: 2.1" x 1.9" x 1.1" (5.3 x 4.8 x 2.8 cm)
Wt: 1.02 oz. (28.9 g)
Dallas Gem Mine, San Benito County, California, U.S.A.
Though most of the Benitoite crystals on this specimen are quite small, there are at least a dozen of them, and most are in excellent condition. Most range in size from 2-5 mm in any dimension, but one particular crystal has dimensions of 0.4 x 0.2 x 0.2" (1.0 x 0.5 x 0.5 mm). All have an excellent trigonal tabular form, and there are 5 crystals other than the dozen or so aforementioned that are damaged and incomplete due to the specimen's separation from its place of origin. All of the Benitoites have a moderate grayish-blue coloration and show a dull, pearly-to-waxy luster. They are dimly transparent, so that one can see that all have considerable internal fracturing. They rest on an almost massive natrolite crust, and are accompanied by at least 20 prismatic neptunite crystals that have excellent form, a black color, and a vitreous luster. Though there is no image of it, the Benitoites glow a bright blue under shortwave UV radiation- one might be surprised at just how much Benitoite is on this piece.
ben-5 ($310.00)Dallas Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-6
$ 90.00
$ 90.00
Dims: 0.9" x 0.7" x 0.5" (2.3 x 1.8 x 1.3 cm)
Wt: 5.0 g
Gem Mine, San Benito County, California, U.S.A.
This small thumbnail specimen is actually quite impressive, even though it consists of only 4 or 5 intergrown Benitoite crystals. This is due to the fact that one of the crystals is so large that its dimensions match that of the entire specimen! The other crystals are much smaller and grow off of the larger one, which acts as a base. Though there is a small amount of human-induced damage, the crystals are in generally good condition. The largest one is not quite complete, as it is missing noticeable portions due to aberrant growth conditions and intergrowth with the surrounding base rock and associated minerals- there is a small amount of shapeless natrolite still attached in one area. Substantial portions of the crystal have a distinctly green coloration that may be caused by dust from the host rock in which it grew, but its deep blue coloration is still visible in some areas. It also shows only moderate to dim translucence in strong sunlight, but the smaller crystals show definite transparence in some areas. All have the standard trigonal tabular form, though the smaller crystals show some warping due to their intergrowth. Besides the bit of natrolite and some greenish, powdery material that lines some of the underdeveloped areas, there is no host rock.
ben-6 ($ 90.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-7
$ 90.00
$ 90.00
Dims: 1.5" x 0.7" x 0.5" (3.8 x 1.8 x 1.3 cm)
Wt: 3.6 g
Gem Mine, San Benito County, California, U.S.A.
At least 10 minute Benitoite crystals rest on the natrolite host rock of this small specimen. All are in excellent condition, showing no human-induced damage, and have good trigonal tabular form that is only slightly warped due to their intergrowth. The largest of these crystals has visible dimensions of 0.3 x 0.2 x 0.1" (0.8 x 0.6 x 0.2 cm) and, like all of the others, has a moderate to deep blue coloration and a bright vitreous luster. All are transparent and show areas of clarity, though the larger crystals are mostly clouded with veil-like inclusions. They glow a beautiful, bright blue under shortwave UV light.
ben-7 ($ 90.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-8
$ 90.00
$ 90.00
Dims: 0.9 x 0.5 x 0.5" (4.8 x 1.3 x 1.3 cm)
Wt: 4.2 g
Gem Mine, San Benito County, California, U.S.A.
Four trigonal tabular Benitoite crystals rest on a natrolite crust that partly covers the gray host rock of this thumbnail specimen. These crystals range in diameter from less than 2 mm to 0.4" (1.0 cm), and are generally in excellent condition; only one shows any damage, and it is still complete. All have excellent form, with well-defined edges clean faces that possess a surprisingly dull, pearly luster. The largest crystal has a slight irregularity in its form, but this does not affect its overall shape. Their color ranges from pale to deep blue, and all are at least translucent and contain areas of noticeable transparence amid their slight internal fracturing.
ben-8 ($ 90.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-9
$ 35.00
$ 35.00
Dims: 2.1 x 1.7 x 1.1" (5.3 x 4.3 x 2.8 cm)
Wt: 1.54 oz. (43.7 g)
Gem Mine, San Benito County, California, U.S.A.
This thumbnail specimen consists of a cluster of broken and incomplete Benitoite crystals that rest on the edge of a gray host rock. Because of the high level of breakage, it is very difficult to determine the size of the crystals, but one appears to have measured at least 0.4" (1.0 cm) in diameter when it was complete. A few incomplete faces and edges are the only evidence of hexagonal form, and the rough, fresh breakage surfaces have a vitreous luster. All have the moderately pale, uneven blue coloration that is standard for this mineral, and they are noticeably transparent in some areas, though they are mostly translucent due to heavy internal fracturing. The gray host rock on which they rest is partly coated with a crust of massive, white natrolite.
ben-9 ($ 35.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-10
$ 42.00
$ 42.00
Dims: 2.1 x 1.4 x 0.6" (5.3 x 3.6 x 1.5 cm)
Wt: 12.4 g
Benitoite Mine, San Benito County, California, U.S.A.
This is the first Benitoite specimen that I have seen from the Benitoite Mine- all others came from the Gem Mine. All three crystals on this thumbnail specimen are at least slightly broken and incomplete. The largest has dimensions of 0.8 x 0.8 x 0.4" (2.0 x 2.0 x 1.0 cm) and appears to be less than 50% complete, with large fresh breakage surfaces. Oddly, the least complete crystal has the least amount of fresh breakage on its surface. Only the two larger crystals show any discernable hexagonal form, and this form occurs only as a few incomplete faces and edges. All have a moderate, patchy blue coloration and a vitreous luster, but are cloudy and translucent. They rest on a small amount of a dull, pale gray host rock that is partly encru
ben-10 ($ 42.00)
Benitoite Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-11
$ 47.00
$ 47.00
Dims: 1.6 x 1.5 x 0.8" (4.1 x 3.8 x 2.0 cm)
Wt: 13.2 g
Gem Mine, San Benito County, California, U.S.A.
Three Benitoite crystals rest on the pale gray host rock of this thumbnail specimen. Each of these crystals is considerably damaged, and none are complete. They do not exceed 0.3" (8 mm) along an edge and where intact, show good hexagonal prismatic form, with sharp edges and clean faces. All have a coloration that ranges from white to deep blue to blue-gray and a luster that ranges from vitreous to pearly. Two of the crystals are translucent and show patches of transparence, but the other is essentially opaque. All glow a bright blue under shortwave ultraviolet light (see the second image). Only a small amount of white, massive natrolite accompanies them.
ben-11 ($ 47.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-12
$ 40.00
$ 40.00
Dims: 1.8 x 1.0 x 0.5" (4.6 x 2.5 x 1.3 cm)
Wt: 10.0 g
Gem Mine, San Benito County, California, U.S.A.
At least 11 separate and distinct Benitoite crystals rest on the gray base rock of this thumbnail specimen. The largest crystal has a diameter of 0.4" (1.0 cm), and along with the 2 other largest, is the most exposed. Each one of them is damaged and incomplete. Most of the smaller crystals, however, are intact and show good trigonal tabular form, with well-defined edges and clean faces. Their color is a moderately deep gray-blue and translucent, and all have a dull, waxy luster. They rest in, on, and around a small, thin crust of white natrolite that partly coats the base.
ben-12 ($ 40.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-13
$ 45.00
$ 45.00
Dims: 1.2 x 1.1 x 0.4" (3.0 x 2.8 x 1.0 cm)
Wt: 8.6 g
Benitoite Gem Mine, San Benito County, California, U.S.A.
The pale gray base rock of this thumbnail specimen holds 3 Benitoite crystals. All of these crystals are damaged and incomplete, and the largest has visible dimensions of 0.4 x 0.2 x 0.1" (9 x 5 x 3 mm). Where intact, their trigonal tabular form is quite good, showing well-defined edges and clean faces that possess a waxy-to-pearly luster. All have the standard, uneven blue coloration and glow a bright blue under shortwave UV light. They are transparent but only dimly clear due to deep color and considerable internal fracturing. A few tiny neptunite crystals accompany them, along with one or two crusts of massive natrolite.
ben-13 ($ 45.00)
Benitoite Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-14
$ 45.00
$ 45.00
Dims: 1.1 x 0.8 x 0.5" (2.8 x 2.0 x 1.3 cm)
Wt: 4.4 g
Benitoite Gem Mine, San Benito County, California, U.S.A.
At least 7 partial Benitoite crystals rest on the gray base rock of this thumbnail specimen. All but one of these crystals shows extensive damage, and the largest measures just under 0.3" (8 mm) along an edge. Where intact, all have very good trigonal tabular form, with well-defined edges and clean faces. Their color is the standard moderate-to-deep blue of their species, their luster ranges from waxy to vitreous from face to face, and all are translucent and heavily internally fractured. They emit the standard bright blue glow when viewed under shortwave ultraviolet light, and are accompanied by a few small patches of massive natrolite.
ben-14 ($ 45.00)
Benitoite Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-15
$ 60.00
$ 60.00
Dims: 1.5 x 1.4 x 0.7" (3.8 x 3.6 x 1.8 cm)
Wt: 15.7 g
Benitoite Gem Mine, San Benito County, California, U.S.A.
At least 5 Benitoite crystals rest on the gray base of this thumbnail specimen. Two of these crystals are broken and incomplete, but the rest are intact and in excellent condition. The largest crystal is one of the intact ones, and has visible dimensions of 0.4 x 0.2 x 0.1" (1.0 x 0.5 x 0.3 cm). It is incomplete due to growth restrictions and is partly embedded in its base, but like the others has excellent trigonal tabular form, with well-defined edges and clean faces. All of the crystals have a moderate-to-deep-blue color and a vitreous luster, and are transparent and dimly clear, being somewhat internally fractured. Like most of their species, these crystals glow a bright blue under shortwave UV light. They are accompanied by several small neptunite crystals, the larger of which are broken. All are partly embedded in a crust of massive white natrolite that partly coats the gray base rock.
ben-15 ($ 60.00)
Benitoite Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-16
$ 32.00
$ 32.00
Dims: 0.9 x 0.8 x 0.4" (2.3 x 2.0 x 1.0 cm)
Wt: 4.9 g
Gem Mine, San Benito County, California, U.S.A.
Five Benitoite crystals rest on the pale gray base of this thumbnail specimen. All but one of these crystals is broken and incomplete, and the complete crystal is the smallest, measuring 0.1" (3 mm) in diameter. Where intact, all have excellent trigonal tabular form, with well-defined edges and clean faces. These faces show a rather dull, pearly luster, whereas fresh breakage surfaces possess a vitreous luster. All have a deep blue coloration and are at least translucent but heavily internally fractured. As with most Benitoite crystals, these glow a bright blue under utraviolet light. They are separated from the base rock by a layer of massive white natrolite.
ben-16 ($ 32.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-17
$ 28.00
$ 28.00
Dims: 1.8 x 1.1 x 0.7" (4.6 x 2.8 x 1.8 cm)
Wt: 18.3 g
Gem Mine, San Benito County, California, U.S.A.
Eight Benitoite crystals are partly embedded in the gray-and-white host of this specimen. All but 2 of the crystals measure less than 0.1" (3 mm) in diamter, and one of the 2 larger crystals is broken and not quite complete. The other is intact and has excellent trigonal tabular form, with sharp edges and clean faces. All colored a pale gray-blue or a deep blue and have a rather dull pearly-to-waxy luster. They are essentially translucent, and the larger crystals are visibly internally fractured. They glow a bright blue under shortwave ultraviolet light and are partly buried in massive natrolite crusts that coat the pale gray host rock.
ben-17 ($ 28.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-18$ 320.00
Dims: 3.0 x 2.6 x 1.7" (7.6 x 6.6 x 4.3 cm)
Wt: 5.76 oz. (163.5 g)
Benitoite Gem Mine, San Benito County, California, U.S.A.
This exceptional piece contains at least 15 trigonal tabular Benitoite crystals that range in diameter from 1 mm to 0.7" (1.8 cm). These 15 crystals are generally in good condition, though one or two show some obvious damage, and many other broken and incomplete crystals rest among them. All have a deep sapphire-blue color and a pearly-to-vitreous luster, and are translucent due to the presence of many internal fractures. When bathed in shortwave UV light, they glow a very bright blue (see the second image). The host rock is made up of a gray, chalky rock that resembles serpentine and is partly coated by veins of massive, white natrolite.
ben-18 ($320.00)Benitoite Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-19
$ 30.00
$ 30.00
Dims: 1.2 x 0.7 x 0.6" (3.0 x 1.8 x 1.4 cm)
Wt: 3 g
Gem Mine, San Benito County, California, U.S.A.
This thumbnail specimen consists of a small piece of dull, gray host rock on which rests a single tabular Benitoite. This crystal measures 0.4" (1.0 cm) in diameter and is in very good condition, showing no fresh damage. Its trigonal tabular form is incomplete due to old damage and apparent weathering, but is still rather well-defined. Its color is a dull gray and its luster is dull and waxy- again, both are likely due to weathering. Under shortwave UV light, the crystal glows the standard bright blue, however. It is accompanied by 5 black neptunite prisms. The gray base rock has a substantial amount of glue attached to one side- I am not sure how one would remove it without threatening the integrity of the piece.
ben-19 ($ 30.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-20
$ 220.00
$ 220.00
Dims: 2.1 x 1.3 x 0.8" (5.4 x 3.2 x 2.1 cm)
Wt: 20 g
Gem Mine, San Benito County, California, U.S.A.
Nine or ten trigonal tabular Benitoite crystals are embedded in the artinite matrix of this hand specimen. The largest of these crystals measures 0.5" (1.3 cm) along an edge and is incomplete due to interrupted growth, as are most of the other crystals. Most are also damaged, but the largest one and a few others are intact and in very good condition. All have the standard deep blue color and a rather dull, pearly to waxy luster. They are transparent but cloudy and only dimly to moderately clear. Like all examples of this mineral, these crystals glow a bright blue under shortwave ultraviolet light.
ben-20 ($220.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-22$1020.00
Dims: 5.0x3.5x2.3" (12.7x8.9x5.8 cm)
Wt: 25.5oz. (722g)
Dallas Gem Mine, San Benito County, California, U.S.A.
The matrix of this specimen is host to some of the largest crystals of benitoite I have ever seen. Two of these crystals are 0.7" (1.8cm) on edge! There are at least two dozen crystals of benitoite on this specimen, neptunite crystals ranging from minute up to 0.1" (0.3cm) in length, and a very large number of tiny joaquinite crystals. All of these minerals occur on or within a bed of massive white natrolite, on a matrix of altered serpentine. The benitoites show a play of color on their surfaces as one turns them under a light. Several of the benitoites on this specimen are damaged, mostly near the edges of the specimen. Even with the damaged crystals, this is still an incredible specimen.
ben-22 ($1020.00)Dallas Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-21
$ 180.00
$ 180.00
Dims: 0.9 x 0.6 x 0.4" (2.3 x 1.5 x 1.1 cm)
Wt: 7 g
Gem Mine, San Benito County, California, U.S.A.
This thumbnail piece consists of a single broken, incomplete Benitoite crystal. There is both fresh and old damage on the breakage surface of this crystal, which appears to be almost exactly 50% complete. What trigonal tabular form it has, however, is excellent, with well-defined edges and clean faces. Its color fades from colorless at its center to a deep blue at its edges, and its luster ranges from vitreous to pearly. It is transparent and dimly to moderately clear, and there is no host rock present. It glows brightly under a shortwave UV light source.
ben-21 ($180.00)
Gem Mine, San Benito County, California, U.S.A.
BENITOITE specimen ben-23$ 300.00
Dims:10.2x6.7x4.5" (25.9x17.0x11.4 cm)
Wt: 100oz. (2.8kg)
Dallas Gem Mine, San Benito cty., California
This is an incredible multiple-species specimen. At least two dozen partial or complete crystals of benitoite are scattered over this specimen. The largest crystal I found was just under 0.4" (1.0cm). Next, there are over 100 crystals of neptunite ranging in size from tiny to one monster 1.6" (4.1cm) in length. Many of these neptunites have excellent terminations. Finally, there is a small amount of tiny, acicular crystals of joaquinite on one edge of this specimen. These joaquinite crystals show a very dim yellow-brown fluorescence under short-wave ultraviolet light. All of these crystals are thrusting out of a bed of massive white natrolite. The natrolite is deposited on an altered serpentine host material. This is quite an impressive specimen.
ben-23 ($300.00)Dallas Gem Mine, San Benito cty., California
BENITOITE specimen ben-24
$ 35.00
$ 35.00
Dims: 2.4x2.0x0.5" (6.0x5.0x1.4cm)
Wt: 1.10 oz. (31.1g)
Benitoite Gem Mine, New Idria District, San Benito County, California, USA
This specimen has 4 benitoite crystals exceeding 1cm in length, and a dozen tiny ones. Some of the smallest have excellent form, but the larger crystals all are distorted and coated with some of the matrix from the "other" side of the cavity. There are two small neptunite crystals at one end with perfect form and color, but the interesting neptunite crystal appears weathered to a brown color, it attached to the largest of the benitoites, and the fractured surfaces at one end is a deep red and flashes intensely red from some angles when viewed with a loupe.
ben-24 ($ 35.00)
Benitoite Gem Mine, New Idria District, San Benito County, California, USA