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A big surprise at the Denver 2009 show was the appearance of what were widely being called among the world's best demantoid garnets; and in smaller numbers what are absolutely the world's best examples, without compare, of the rare topazolite garnet variety. These come from a remote deposit that is quite literally situated in a tidal-flooded mangrove swamp, near the town of Nosy Faly in Madagascar. Within a short time of their discovery, they had come to the attention of Dr. Federico Pezzotta of the Natural History Museum of Milano (after whom the new Madagascan beryl species Pezzottaite was named), an expert on both mining and the mineralogy of Madagascar. Dr. Pezzotta soon was able to facilitate the valuation and legal export of most of this material. In Tucson, he gave a talk on this locality, and the difficulties of mining there, from which the below information is taken with his permission. As well, through his sources I was able to obtain a very good mixed lot of specimens from this find, including both Demantoid and Topazolite garnets, in a variety of size and price points. ALL SPECIMENS WERE HAND-SELECTED FOR ME AT THE MINES, AND ARE (UNLIKE MOST) GENERALLY PRISTINE AND FREE OF DAMAGE!
The deposit is literally situated in a mangrove swamp, that floods each afternoon at high tide. The waters come in so fast, that I am told you have only a few minutes to clear the mining holes once it starts to come up from the ocean. And, the miners work til the last moment, to gain precious rock to sort later. Dr. Pezzotta has photos (below) showing both low tide with the working pits and their straw mat dividers; and then showing a higher rising tide...but could not ever get a shot at full tide because everybody must leave to walk 1.5 kilometers to "higher ground" ( - thus, nobody is around to take the photo at sunset when the tide is highest and completely covers all workings, huts, and barriers).
The garnet-bearing region on its surface measures about 400 x 400 meters, and is a hard rock to mine in. Nothing is on the surface, and the deposit was discovered completely by accident when locals found shards of garnet in the sections of rock exposed by ocean erosion lower down towards the coast. In this small region, now nearly completely denuded of its original mangrove covering, Dr. Pezzotta counted approximately 800 INDIVIDUAL mining holes, dug to various depths and without any regard for geology or mineralogy. They are dug quite literally at random and some people will dig for days to go down to depths (with HAND TOOLS only!), even after being advised that the rock may not be under them. 800 holes requires 800 teams of diggers, haulers, and sorters; and so you can imagine the crowd during working hours of some 2000-2500 people in this swamp, all flowing in and out with the tides of water. To reach the garnet layer, the miners have to dig straight down (literally, in vertical, rope "hanging seats"), 10-20 meters below the surface. When they hit garnet-bearing rock, they then branch sideways, each miner's group making their own tunnels where they wish and without apparent regard for the gradually honeycombing structure of the rock caused by other mining teams above, beside, and below them. Each "mining group" is actually a family or group of friends, working in teams to do this digging in a rush during the daylight hours, and when the water allows. Each team must start the day when the tide recedes, around 4 AM (after walking 2 kilometers from town), by spending 4-6 hours pumping water manually through a series of pipes and tubes to access their holes.
Then, they have several hours to frantically dig - hauling buckets out as fast as they can, for later sorting in the tidal pools by other team members. For the very ambitious workers, they all haul buckets and get to the sorting after hours - after carrying the heavy buckets to the high tide line 1.5 kilometers away. The problem is, obviously, that the holes fill each night with the tide. Between the tides and rainwater filling the holes, digging here is absolutely impossible in the rainy season and so all mining has ceased for the moment. It is an open question of whether it will be economical (and safe) to continue digging when the drier season of 2010 comes around. Given the conditions, the working with hand tools in small one-man holes, and the urgency of digging quickly, it is easy to see why so few perfect specimens are obtained. Most of what is recovered are smashed crystals simply hacked off the rock for any quick faceting value that can be yielded from the buyers in the wholesale gem trade. < NOTE ON GEOLOGY: This deposit is unique. Studies by Dr. Pezzotta and his former graduate student Dr. Emanuele Marini, have confirmed that the main body of sedimentary rock here has been altered over geological time to a fine-grained garnet. The seemingly limestone matrix is so hard and strong for a reason - it is not limestone! Per Dr. Marini: The matrix is mainly sedimentary rock (sandstone) metamorphised by lamprofiric dikes cross cutting the sedimentary deposit. On many matrix you see micricristalline garnet or the relict structure of the sedimentary rock. On few specimens you can see fossils. The demantoides formed in the fractures of the sedimentary rocks and yes, sometimes the matrix is micro-xls of demantoid with a growth of larger xls on them. Metasomatism is a serie of chemical reactions that bring a partial recrystallization with variation of its compounds: so, we can consider the demantoides a product of the metamorphism inducted by the intrusions of the lamprofiric dikes in the sedimentary rocks. All the garnets crystallized in the fractures are andradite, the Titanium member of the series. In some matrix closeups, the whiter style, you can observe some small sub-mm creamy xls. Actually these are andradite garnet as well, but with a conspicuous grossular component. The only associations are some quartz and (very rare and unusual!), stilbite.
(Federico Pezzotta specimen and photo)
MADGARN-01 - Andradite var. Demantoid garnet - $ 1200 SOLD Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar thumbnail, 1.7x 1.7 x 1.5 cm
A stunning thumbnail, one that rgabbed me amidst hundreds of simply "small specimes" I have seen, as a piece with balance and significance that shows best in this size range, and not just "a small rock." This piece features a large, glassy and gemmy, grass-green demantoid crystal, measuring 1.7 cm in length, framed by smaller crystals. All of them are perched on a natural little pedestal of matrix and the cluster is complete all around. MUCH BETTER in person.
MADGARN-02 - Andradite var. Demantoid garnet - $ 1800 SOLD Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar miniature, 3.9 x 3.5 x 3.0 cm
This is a cluster of glassy and gemmy, richly green, demantoid crystals reaching 1.1 cm in length. The cluster is rich and bright, and the crystals cascade nicely across the matrix. The display crystals are pristine and show all faces save only for the large crystal on the right , which exhibits the contact outline of a previously attached crystal. The white matrix was actually limestone which has been, amazingly, metamorphosed ( metasomatized) into garnet in ancient geological time. Incredible origins for a matrix garnet specimen, and yet another reason to value this new deposit so highly.
MADGARN-03 - Andradite var. Demantoid garnet - $ 250 SOLD Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar miniature, 3.3 x 2.4 x 1.8 cm
Two sharp, glassy and gemmy, olive-green demantoid crystals , to 1.2 cm in length, are perched on a garnet matrix. Both crystals exhibit unusual and evident hoppered growth, which is rare in the garnet family. Riveting for the symmetry and sharp forms, this is a fine small miniature or, trimmed at bottom, a killer thumbnail specimen
MADGARN-04 - Andradite var. Topazolite garnet - $ 400 SOLD Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar miniature, 3.5 x 2.4 x 2.2 cm
Aesthetically nestled in a vug of metamorphosed (metasomatized) garnet matrix is a cluster of well formed, glassy and gemmy, olive-green and cognac-colored, andradite var. topazolite crystals. The color is really complex, and a mixture of green and brownish hues. The lustre is through the roof, really bright and glassy! The largest crystal measures 1.5 cm in length. The crystals are so gemmy you can look through them to the matrix underneath. This is a small miniature, in person, but a very bright one with high impact. It is hard to convey the quality of the bright lustre in photos.
MADGARN-05 - Andradite var. Demantoid garnet with Stilbite - $ 1750 SOLD Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar miniature, 3.2 x 2.6 x 2.4 cm
A cluster of glassy and gemmy, brilliant green, demantoid crystals has grown on and with an ivory colored matrix of stilbite crystals, to 5 mm in length. The largest demantoid is 1 cm in length. This is an unbelievable melding of stilbite and demantoid in associatio - you don't see that from anywhere else I am aware of (nor is Dr. Pezzotta) and it seems another element of the geological puzzle that produced this locality. Most stilbite is micro, and very few specimens of any quality host both good demantoid and stilbite together. This is a superb, showy miniature, one of only 3 such association pieces I obtained. Even without the stilbite, though, the garnet is of very high quality, color intensity, and crystal size for the find. Although small overall, this is hands down one of my favorites in the lot.
MADGARN-06 - Andradite var. Topazolite garnet - $ 400 SOLD Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar thumbnail, 2.1 x 1.9 x 1.6 cm
This amazing LARGE crystal of andradite var. topazolite, is larger than any such I have seen from other locales. It is glassy and gemmy with a lovely cognac coloring. It is VERY transparent, too, especially at the edges. In several places the crystal seems to exhibit hopper growth, very rare in the garnet family. On the bottom, it is contacted, but complete. A significant thumbnail crystal for the species and the find
MADGARN-07 - Andradite var. Demantoid garnet - $ 1500 Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar small cabinet, 5.4 x 3.4 x 3.2 cm
Perched aesthetically on top of the matrix are clusters of demantoid crystals to 1.5 cm in length. The crystals are glassy and gemmy and exhibit an olive green color. I really like the way each cluster is separated from the other, very 3-dimensionally, and shows many faces to maximum effect. Some incipient hopper growth is also noted on one or two crystals, which is unusual. The specimen is a large miniature or small cab , borderline in size. It showcases the crystals ery well and is MUCH better in person. The color is brown-olive, as if it is in between topazolite and demantoid in hue
MADGARN-08 - Andradite var. Demantoid garnet - $ 6000 SOLD Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar cabinet, 15.1 x 10.1 x 6.7 cm
This is an imposing, large specimen of demantoid garnet on matrix. It SPARKLES with color and brilliant facets from hundreds of faces of the gemmy crystals upon it. Few specimens like this have ever come from any of the other demantoid lcoales, in the size and quality range. Nearly covering the surface of this piece are glassy and gemmy green crystals to 8 mm. The matrix is garnet, actually, in a strange twist of geology transformed ( metasomatized) from the original limestone and then serving as host for a later garnet despoition. From this particular deposit, given the difficulty of access, it is VERY uncommon to get good large pieces of any quality. Like others in my lot, I was very careful to purchase pieces without damage and dings (and MOST of the specimens produced had some problems in that regard, as they were hacked out of holes 20-50 meters deep with hand tools, by amateur collectors in a hurry!). That being said, this is a very rare larger piece , with no damage to the display face, despite its broad exposure. One imagines that it was in a lucky large pocket, a rarity at this location where small and tight veins seem the rule.
MADGARN-09A - Andradite var. Demantoid garnet - $ 1200 SOLD Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar miniature, 5.1 x 2.7 x 2.3 cm
Discrete crystals of glassy and gemmy, rich green demantoid crystals, to 1.2 cm in length, are nicely perched on a metasomatized, garnet matrix. This piece has garnets that are unlikely survivals on the matrix…they are so 3-dimensional and upright, its hard to believe they didn't just pop off in collecting. But there they are, some of the sharpest, most 3-D and isolated, of this lot. The lustre is liek glass, really high for this species.
MADGARN-09B - Andradite var. Demantoid garnet - $ 200 SOLD Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar thumbnail, 1.9 x 1.7 x 1.5 cm
A single glassy and gemmy, light green crystal of demantoid, measuring 1.3 cm across, is aesthetically perched on a natural pedestal: the matrix is made up of limestone metasomatized (metamorphosed to) microscopic garnet so this is technically garnet on garnet! The garnet is complete all around save only a small contact on back. A fine thumbnail of high quality for its good color, and excellent translucency.
MADGARN-09C - Andradite var. Demantoid garnet - $ 750 Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar small cabinet, 6.2 x 3.9 x 2.5 cm
Highlighted by a large, unusually elongated, nearly 2 cm-long demantoid crystal, this matrix specimen has several, glassy and gemmy, light green, discrete crystals perched on the contrasting matrix. VERY fine example with good color, lustre, and translucency for the price and size ranges.
MADGARN-10 - Andradite var. Demantoid garnet - $ 1250 Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar small cabinet, 6.2 x 5.0 x 1.4 cm
A thin plate of intergrown, glassy and gemmy, olive-green, demantoid crystals! The crystals, to 1.2 cm in length , are emplaced on a thin plate of (metamorphosed) metasomatized garnet matrix. Striking specimen for the sparkle and richness of the crystallization. All of these crystals are SO gemmy, and transparent, that you can look right through them to the matrix beneath. Superb, bright specimen, and a lot of demantoid for the price, I felt
MADGARN-11 - Andradite var. Topazolite garnet - $ 400 SOLD Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar miniature, 4.7 x 3.2 x 2.0 cm
A cluster of glassy and gemmy topazolite crystals, to 1.2 cm in length, has nearly covered the metasomatized garnet matrix. These are bright and lustrous, and very gemmy! You can see the matrix through the crystals. The color is brown-olive, as if it is in between topazolite and demantoid in hue
MADGARN-12 - Andradite var. Demantoid garnet - $ 750 Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar miniature, 5.2 x 3.8 x 2.1 cm
Intergrown crystals of glassy and gemmy, olive green colored demantoid crystals, to 2 cm in length, form a solid plate on thin matrix. The crystals are elongated, and totally gemmy! They are glassy and transparent, so you can look right through them all, like little jewels. A beautiful and unusual plate from this locale
MADGARN-13 - Andradite var. Topazolite garnet - $ 1250 SOLD Antetezambato, Ambanja District, Diana Region, Antsiranana Province, Madagascar miniature, 4.6 x 4.1 x 2.9 cm
A superior example by any standard of the topazolite variety of garnet: Highlighted by a large, robust 2 cm crystal, these glassy and gemmy, cognac-colored andradite var. topazolite crystals sit on a matrix of metsomatized (metamorphosed from limestone) garnet. An elegant and superb specimen with a dominating main crystal atop, this is an important example of the species.
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