SPINEL
Specimen spi-17

Dims: 3-1/2" x 2/38" x 2-1/8"

Wt: 8.1 oz

MacDonald Island vicinity, Northwest Territories, Canada

This specimen is composed of delightfully large (up to 3/4 inch diameter), black Spinel crystals in a white crystalline matrix whose identity I can't figure out. These crystals look a lot like blue-black garnets, in a cubic crystal shape that I'm having trouble digesting, as there are 4-, 5-, and 6-sided faces on every crystal. This is a super-neat piece, and the first raw Spinel crystals that I've ever laid eyes on.

Dims: 7/8" x 3/4" x 1/2"

Wt: 8.1 oz

Parker Mine, Notre Dame de Laus, Quebec, Canada

This Spinel cluster is made up of 5 discernable crystals, the largest of which is almost 3/4" across its longest axis. All are black and opaque, with what seem to be blue-black highlights. They also all show the classic octahedral crystal shape, and have a dull luster, with some heavy scratching on the crystal faces. Only one of the crystals is complete, whereas the other four are all missing portions. There is no visible host rock. This is one of the better thumbnails I've seen.

Dims: 0.3" x 0.3" x 0.3"(0.8 x 0.8 x 0.8 cm)

Wt: 3.15 ct

near Mogok, Burma

This specimen consists of a somewhat warped but nearly complete octahedral crystal of Ruby Spinel. Though lacking perfect symmetry and form, there is only one spot of obvious damage along one edge of the crystal. Its faces show considerable growth patterning and its edges are stepped and show considerable wear, but its form is definite. Its color is a deep, ruby-red, and it has a vitreous luster. It is transparent but contains many internal flaws and fractures. I jumped at the chance to buy some of these- they are the only ones that I found at the shows.

Dims: 0.4" x 0.3" x 0.3"(1.0 x 0.8 x 0.8 cm)

Wt: 4.45 ct

near Mogok, Burma

A rather heavily damaged Ruby Spinel octahedron constitutes this Burmese specimen. Its octahedral form is slightly flattened, and 3 of its points are damaged, showing conchoidal chipping. Two of the intact points, however, show natural notching, indicating slight Spinel-Law twinning. The faces are generally clean and the edges, though somewhat rounded, are definite. Its color is bright red, it has a vitreous luster, and it is transparent, though many internal fractures and a few veil-like inclusions interfere with its clarity. It does, however, come from a well known Spinel-producing area of the world, and we have had trouble finding such specimens. Besides, its color is splendid!

Dims: 1.7 x 1.4 x 0.6" (4.3 x 3.6 x 1.5 cm)

Wt: 19.4 g

Notre Dame du Laus, Quebec, Canada

This small thumbnail specimen consists of a cluster of heavily-intergrown Spinel crystals that are partly embedded in a small amount of pale orange calcite. I count at least 7 different crystals, or attempts at the formation of individual crystals- as most of them are aligned with each other, I suppose that one could refer to the cluster as a single unit. All are in excellent condition, showing no human-induced damage, and together, have dimensions of 0.5 x 0.4 x 0.4" (1.3 x 1.0 x 1.0 cm). Their octahedral form is quite good, considering their intense intergrowth, and all edges are relatively well-defined, and all primary and secondary faces are flat, generally clean, and possess a bright pearly luster. Their color is basic black, and thus they are all opaque.

Dims: 2.8 x 1.9 x 1.6" (7.1 x 4.8 x 4.1 cm)

Wt: 5.05 oz. (143.2 g)

Aliabad, Hunza, Northern Areas, Pakistan

At least 7 Spinel octahedrons rest in the white host rock of this hand specimen. These crystals generally do not exceed 0.1" (3 mm) in diameter, but one is much larger, having a diameter of 0.3" (8 mm). Most are in excellent condition, showing no damage, but one or two are visibly damaged, and one is mostly incomplete. Their octahedral form is excellent- all have well-defined edges and clean faces that possess a rather dull, pearly luster. Their color is a rather dull, deep violet, and only the smaller crystals are visibly transparent. The largest crystal shows patches of shallow transparence, but is moderately to dimly translucent as a whole. They are accompanied by several small and generally incomplete muscovite books that have a pale brown color and are impressively clear. The host rock in which all of these rests is quite calcareous, though I believe that it contains a substantial amount of feldspar.

Dims: 0.5 x 0.5 x 0.3" (1.3 x 1.3 x 0.8 cm)

Wt: 6.3 g w/ base

Muchara Nala, Hunza, Northern Areas, Pakistan

This small thumbnail specimen consists of at least 3 Spinel octahedrons that are partly embedded in a white pegmatite base. Two of these octahedrons are partly intergrown, whereas the third (and largest) is isolated. The smaller crystals do not exceed 0.1" (3 mm) in diameter, but the larger one measures 0.3 - 0.4" (8 - 10 mm) in diameter. However, this large crystal is only about 60 - 70% complete and shows slight but visible damage, whereas the smaller crystals, apart from their intergrowth, are essentially complete and undamaged. Their octahedral form is generally very good, with well-defined edges and clean faces that possess a pearly luster. All have a dull, deep violet coloration. The larger crystal is generally dimly translucent, showing small areas of transparence, whereas the smaller crystals are dimly transparent under bright light. They are accompanied by a few broken, pseudohexagonal muscovite books. The piece is attached to a small acrylic base with a removable putty.

Dims: 1.7 x 0.7 x 0.5" (4.3 x 1.8 x 1.3 cm)

Wt: 12.4 g

Aliabad, Hunza, Northern Areas, Pakistan

This small Spinel specimen confuses me a bit. It consists of at least 2 Spinel crystals that are rather heavily intergrown. The larger crystal appears to be slightly damaged and not quite complete, though the smaller one does not show any visible damage. The larger crystal has visible dimensions of 0.3 x 0.3 x 0.2" (8 x 8 x 5 mm), whereas the smaller crystal does not exceed 0.1" (3 mm) in any dimension. Their form is quite odd- it certainly is not octahedral, and does not even appear to be cubic- I cannot define it properly! However, they still have well-defined edges and striated but clean faces that possess a bright pearly luster. Both crystals are colored black and are essentially opaque. The Spinels are accompanied by many rounded muscovite "books" that have a golden-brown coloration and a bright pearly luster. All are embedded in a white, crystalline pegmatite host rock.

Dims: 0.9 x 0.7 x 0.5" (2.3 x 1.8 x 1.3 cm)

Wt: 5.0 g

Muchara Nala, Hunza, Pakistan

At least 3 Spinel crystals rest in the pegmatite host of this thumbnail specimen. Only one of these exceeds 2 mm along any axis- it has visible dimensions of 0.4 x 0.3 x 0.2" (1.0 x 0.8 x 0.5 cm) and looks as if it has been cleaved in one area. All have reasonably good octahedral form, with well-defined edges and slightly striated but clean faces that possess a bright pearly luster. They all have a dull violet color with a hint of red, and are dimly transparent and contain many internal fractures. A very small amount of muscovite is also present, but does not have any appreciable form.

Dims: 0.4 x 0.4 x 0.3" (1.0 x 0.8 x 0.8 cm)

Wt: 3.85 ct

near Mogok, Burma

This small thumbnail specimen consists of a single "Ruby Spinel" octahedron. It is in moderately good condition, showing fresh damage on one corner, and has very good octahedral form that is not quite symmetrical along one axis. It has a ruby-red color and a bright pearly luster, and is transparent and moderately clear, containing a few large internal fractures. There is no host rock present.

Dims: 2.1 x 1.7 x 0.8" (5.4 x 4.3 x 2.1 cm)

Wt: 1.7 oz. (47 g)

Muchara Nala, Hunza, Northern areas, Pakistan

A single, twinned Spinel crystal is partly embedded in the pegmatite matrix of this hand specimen. It has visible dimensions of 0.5 x 0.4 x 0.2" (1.3 x 0.9 x 0.6 cm) and is in very good condition, showing little damage. Its octahedral form has been twinned according to the Spinel Law, and though its form is otherwise slightly warped, the twinning is obvious. The crystal has a deep violet coloration and a slightly dull vitreous luster, and is dimly translucent. The surrounding pegmatite is loaded with small flecks of muscovite and probably biotite.

Dims: 6 x 4 x 3 mm

Wt: 1.2 ct

near Mogok, Burma

This small thumbnail specimen consists of a single Ruby Spinel crystal. The crystal is in very good condition, showing almost no damage, and has an asymmetrical but very well-defined octahedral form. It has a deep, ruby-red color and a vitreous luster, and is transparent and very clear- a few small internal fractures lie near two opposing surfaces, but that is all. There is no base or host rock present.

Dims: 3.9 x 2.8 x 1.8" (9.9 x 7.0 x 4.6 cm)

Wt: 11.6 oz. (330 g)

near Mogok, Burma

This cabinet specimen consists of a calcite matrix in which are embedded at least 4 Ruby Spinel crystals. The largest of these crystals reaches 0.2" (6 mm) in diameter and has the best octahedral form. All have the standard deep ruby-red color and a greasy-to-vitreous luster and are transparent and at least moderately clear. There may be more of these crystals embedded in the gray calcite matrix- maybe careful bathing in hydrochloric acid would be the best way to explore.

Dims: 2.4 x 1.5 x 0.7" (6.2 x 3.7 x 1.7 cm)

Wt: 1.2 oz. (34 g)

near Mogok, Burma

A single, tiny Spinel crystal rests on the quartz base of this hand specimen. The crystal does not exceed 0.1" (3 mm) in diameter but is in exceptional condition. Its octahedral form is likewise excellent, showing well-defined edges and extremely clean faces that possess the standard vitreous luster. The crystal is of a variety known as ruby spinel, and thus has the standard ruby-red color. It is also transparent and extremely clear. The surrounding quartz base shows no crystal form.

Dims: 1.9 x 1.4 x 0.8" (4.8 x 3.5 x 2.0 cm)

Wt: 0.8 oz. (23 g)

Mogok, Burma

A single, tiny Spinel crystal rests in the quartz matrix of this hand specimen. This crystal does not exceed 0.2" (4 mm) in diameter and is in excellent condition, showing no damage. Its octahedral form is nearly perfect, with sharp edges and very clean faces. It has a deep red color and a somewhat dull vitreous luster, and is translucent, containing many internal fractures.

Dims:2.5x2.3x1.4" (6.4x5.8x3.6 cm)

Wt: 3.4oz. (96g)

Baffin Island, Nunavut, Canada

This is a most unusual specimen. Excellent Blue spinel crystals are found in a flesh-colored calcite matrix with diopside and phlogopite mica. There are five exposed spinel crystals on this specimen; one of the smaller ones is damaged. The edges of the spinel crystals are unusually rounded, and they show internal shattering. The largest exposed spinel crystal on this specimen measures 0.5" (1.3cm). This is the single largest crystal seen in this lot of specimens. Also, the calcite on this piece fluoresces a dark purple under short wave ultraviolet light.

Dims:3.5x3.5x2.0" (8.9x8.9x5.1 cm)

Wt: 16.9oz. (478g)

Baffin Island, Nunavut, Canada

This is an excellent specimen! Well over 100 crystals of blue spinel are exposed on a matrix of flesh-colored calcite. Also present is one tiny crystal of phlogopite mica I found while inspecting this piece with a loupe. The spinels have curiously rounded crystal edges. The largest exposed crystal on this specimen measures 0.2" (0.5cm). Some of the exposed crystals show some damage, but most of them are in excellent condition, exhibiting good octahedral form. The calcite fluoresces dark purple in short wave ultraviolet light.

Dims:1.7x1.5x1.0" (4.3x3.8x2.5 cm)

Wt: 1.4oz. (41g)

Baffin Island, Nunavut, Canada

More than 20 crystals of blue spinel are exposed on the calcite and phlogopite matrix of this specimen. The edges of these spinel crystals are curiously rounded-they almost appear tumbled. The largest crystal measures 0.2" (0.5cm). A few of these crystals show some damage, but most are undamaged exhibiting good octahedral form. On one corner of the specimen is a shattered mass of blue crystalline spinel. It does not show crystal faces, and measures 0.7" (1.8cm) across. The calcite matrix is fluorescent dark purple under short wave ultraviolet light.

Dims:1.2x1.2x0.5" (3.0x3.0x1.3 cm)

Wt: 0.5oz. (13g)

Baffin Island, Nunavut, Canada

A large spinel crystal, along with several small ones, is exposed on the calcite matrix of this specimen. Also present in the matrix are phlogopite and diopside. The large spinel measures 0.3" (0.8cm) across; there is a small amount of damage on the underside of this crystal. Otherwise, it shows shows good octahedral form. These spinels exhibit curiously rounded crystal edges. The calcite matrix fluoresces dark purple under short wave ultraviolet light.

Dims:1.3x0.8x0.8" (3.3x2.0x2.0 cm)

Wt: 0.8oz. (24g)

Baffin Island, Nunavut, Canada

This specimen consists of a large euhedral blue spinel crystal on a matrix of flesh-colored calcite. This crystal measures 0.2" (0.5cm) across, and exhibits a distorted octahedral form. There are at least 6 other spinels on this specimen. They range in size from tiny to small; two of them are intergrown with the large crystal. The edges of these spinels are curiously rounded, giving the crystals a tumbled appearance. The calcite matrix fluoresces dark purple under short wave ultraviolet light.

Dims:1.6x0.9x0.8" (4.1x2.3x2.0 cm)

Wt: 1.0oz. (27g)

Baffin Island, Nunavut, Canada

This specimen consists of several blue spinel crystals in a matrix of calcite and diopside. The largest crystal measures 0.2" (0.5cm) across, but is damaged on one side. The other crystals in this specimen are intact, however, and exhibit good octahedral habit. The edges of these spinels are curiously rounded. The calcite matrix fluoresces dark purple under short wave ultraviolet light.

Dims:1.3x1.2x0.5" (3.3x3.0x1.3 cm)

Wt: 0.9oz. (25g)

Baffin Island, Nunavut, Canada

This specimen consists of several blue spinel crystals in a matrix of flesh-colored calcite. Traces of phlogopite and diopside also are found in the matrix. The largest spinel crystal measures 0.2" (0.5cm) across and exhibits octahedral habit. All of the spinels show the rounded crystal edges typical of this occurence. This specimen shows only minor damage. The calcite fluoresces dark purple under short wave ultraviolet light.

Dims:1.1x1.0x0.7" (2.8x2.5x1.8 cm)

Wt: 0.7oz. (20g)

Baffin Island, Nunavut, Canada

A single blue spinel crystal measuring 0.3" (0.8cm) is embedded in a matrix of calcite, diopside, and phlogopite. This crystal is undamaged and shows some translucence when held up to a light. The edges of this spinel crystal are extremely rounded, giving the appearance of a tumbled stone. The crystal form appears to be that of a distorted octahedron. The calcite fluoresces dark purple under short wave ultraviolet light.

Dims:3.0x2.6x1.7" (7.6x6.6x4.3 cm)

Wt: 9.1oz. (257g)

Baffin Island, Nunavut, Canada

Approximately 30 blue spinel crystals are scattered over a matrix of calcite, diopside, and phlogopite. These crystals are small, averaging only 0.1" (0.3cm). Several show moderate to severe damage; also shown are the curiously rounded crystal edges that seems to be the norm for this locality. Some of these spinels exhibit good octahedral form. The calcite fluoresces dark purple under short wave ultraviolet light.

Dims:0.8x0.6x0.4" (2.0x1.5x1.0 cm)

Wt: 0.1oz. (3g)

Baffin Island, Nunavut, Canada

This thumbnail specimen consists of 4 small blue spinel crystals embedded in a calcite matrix. The 2 largest crystals measure slightly over 0.1" (0.3cm); the smaller crystals may only be examined with the aid of a loupe. The smaller 2 crystals show some damage. However, this does not detract from the specimen. The spinels exhibit the rounded crystal edges that seem to be the norm for this locality. The calcite fluoresces dark purple under short wave ultraviolet light.

Dims:1.1x1.1x0.7" (2.8x2.8x0.7 cm)

Wt: 0.4oz. (12g)

Baffin Island, Nunavut, Canada

This specimen consists of several intergrown blue spinel crystals in a calcite host rock. The largest spinel crystal measures 0.2" (0.5cm) in length. With the aid of a loupe, traces of diopside are visible in the matrix. Some of the spinels show some damage, although the larger crystals seem to be intact. These spinels show the curiously rounded crystal edges that seem to be the norm for this locality. The calcite matrix fluoresces dark purple under short wave ultraviolet light.

Dims:2.2x2.0x1.7" (5.6x5.1x4.3 cm)

Wt: 3.7oz. (104g)

Baffin Island, Nunavut, Canada

This specimen consists of an intergrown crystalline mass of blue spinel crystals in a calcite, phlogopite, and diopside matrix. There is considerable damage to most of the spinels; however, one intact crystal measures 0.3" (0.8cm) in length. The spinels exhibit the curiously rounded crystal edges seen in all the specimens from this locality. The calcite in this specimen fluoresces dark purple under short wave ultraviolet light.

Dims:2.0x1.1x1.0" (5.1x2.8x2.5 cm)

Wt: 1.4oz. (40g)

Baffin Island, Nunavut, Canada

Several intergrown crystals of blue spinel occur in a matrix of calcite, phlogopite, and diopside in this specimen. The spinels are small, averaging only 0.1" (0.3cm) in size. While a few of these crystals show damage, the majority are intact. The spinels show the curiously rounded crystal edges seen in all the specimens from this locality. The calcite fluoresces dark purple under short wave ultraviolet light.

Dims:1.2x1.0x1.0" (3.0x2.5x2.5 cm)

Wt: 0.8oz. (22g)

Baffin Island, Nunavut, Canada

Several small blue spinel crystals are embedded in a matrix of calcite, phlogopite, and diopside on this specimen. The crystals are small, averaging only 0.1" (0.3cm) in size. Only a couple of the spinels show any damage-the others are intact, with good octahedral form. These spinels show the curiously rounded crystal edges that seems to be the norm for this locality. The calcite fluoresces dark purple under short wave ultraviolet light.

Dims:2.0x1.6x0.9" (5.1x4.1x2.3 cm)

Wt: 1.6oz. (45g)

Baffin Island, Nunavut, Canada

This specimen consists of 2 intergrown clusters of blue spinel crystals in a matrix of calcite, phlogopite, and diopside. These crystal cluster average about 0.2" (0.5cm) in length, and are relatively undamaged. These spinels exhibit the curiously rounded crystal edges typical of this batch of specimens. One side of this specimen is dominated by a large (0.9", 2.3cm) crystal of diopside, showing a shattered interior structure. The calcite on this specimen fluoresces a dark purple under short wave ultraviolet light.

Dims:0.8x0.7x0.5" (2.0x1.8x1.3 cm)

Wt: 0.2oz. (5g)

Baffin Island, Nunavut, Canada

This specimen consists of a crystalline mass of blue spinel, with no matrix present. This was obviously part of a larger crystal, as it exhibits conchoidal fracture on one surface. Two of the other surfaces show the rounding of crystal edges that seems to be typical for this locality. Also present are faces representing a rough octahedral parting. The interior of the crystal shows a shattered crystal structure-this also seems to be the norm for this locality. This crystal shows translucency on its very thin edges.