Dry Storeroom No. 1 (39 page)

Geology evidently requires patience. Nowadays carbonatites are recognized all over the world, from different geological ages, some of them even in very ancient rocks dating from the Precambrian. But as more has been learned about them, the more interesting they prove to be. Frances Wall glows with magmatic enthusiasm on the subject, while Alan Woolley erupts in chortling flows of words. Some of the most curious carbonatites have proved to have diamonds in them. This tells us that they originate not from the higher levels of the crust where sedimentary limestones are normally found, but from very deep down inside the Earth—even from the mantle, where temperatures and pressures are enough to convert the dross of carbon into sparklers, albeit rather small ones. It seems that this kind of carbonatite is extruded from “tubes” punched deep through the lithosphere. Occasionally, these conduits carry up lumps of dark mantle material, displaced messengers from the depths, as happens near the Monticchio Lakes in Italy. Quite commonly, little balls, or spherulites, of graphite about a millimetre across can be separated from the samples, and these are believed to have originated from the parent magma at a temperature about 700 degrees centigrade. Frances has been pursuing carbonatites in fieldwork in the southern Naratau Mountains of Uzbekistan; this undulating area of arid nothingness at the western end of the Tien-Shan would tempt only a geologist or an ascetic seeking mortification of the flesh; or possibly someone in search of the way diamonds form in nature. Once samples had been collected, experimental work could continue back at the laboratory: if a sample of the Uzbek carbonatite rock is seeded with graphite and then the mixture is melted under great pressure, the conditions needed for diamond formation can be replicated. It turns out that diamonds precipitate out at a pressure of 7Gpa and a temperature range of 1,200–1,570 degrees centigrade. It seems that if conditions were extreme enough diamonds might be formed within the carbonatite magma itself deep within the Earth.

Yet another bleak area yielding carbonatites embraces the boundary between Finland and Russia: the Kola Peninsula. Endless forests of dwarf conifers and glacial lakes give way to boggy permafrost, the kind of landscape that swaps freezing winter wastes for a brief episode dominated by summer mosquitoes. In this remote region carbonatites were formed in a different way from “pipes” penetrating deeply into the Earth’s innards. Instead, they formed at depth in the Earth’s crust during a phase of intrusion of a great body of hot igneous magma, one that was already particularly enriched in sodium and potassium. A kind of distillation of magma operates here. As more and more minerals are crystallized out, the remaining magma becomes progressively richer in the “leftovers”: volatile components, or elements which have particular affinity for sodium, or even awkward elements that are reluctant to fit in anywhere else. It is a process of progressive refinement, and—like the business that goes on in an oil refinery—several different products can be produced according to local circumstances. Many volatile fluids invade the country rocks, where they crystallize slowly in fissures, to form
pegmatites
—the source of some of the most perfect and beautiful minerals. Bathed in fluids and gases, these crystals can slowly grow to perfection, as if to please a godly gemmologist, every face perfectly sculpted, and their design naturally determined by their constituent atoms. But because these are carbonatite magmas, the pegmatites contain minerals that are found nowhere else on Earth—they have been enriched in rare elements that provide the ingredients for a host of unusual chemical compositions. The elements concerned include names such as Lanthanum and Yttrium—the rare elements mentioned above. The bleak wastes of the Kola Peninsula provide an unrivalled diversity of strange species of minerals, a gem-hound’s dream. Some of them are as beautiful as rubies, though far, far more rare. Frances Wall and her colleagues have produced a catalogue of these species, a concatenation of odd names like Scherbakovite or Kovdorskite (colour plate 15), which immortalize a bunch of Russian mineralogists and place-names. When the Natural History Museum started working in the Kola, the local Russian mineralogists compiled a shopping catalogue of minerals available there: not one of these minerals was represented in the collections in London. Now we have at least a selection; everyone benefits from international collaboration. Nor are minerals containing rare earth elements of purely academic interest. These elements are of increasing importance in the electronics industry, and wise money is moving into this area, with the unfailing instinct that money always has for the coming thing.

The public gallery displaying the minerals is unusual in the Natural History Museum in also housing the bulk of the collections. For the rest of the Museum departments the collections are so vast that only a tiny part of them is actually in the galleries. Furthermore, every gallery elsewhere in the Museum has been revamped over the last couple of decades, but the mineral display at the eastern end of the first floor has been preserved in something like its original state. The Victorian Society is delighted. It is an airy space, well lit from the generous windows, and with glass-topped cabinets running in ranks transversely across the gallery, each of which includes a fine selection of specimens. The arrangement of minerals in the cases is by natural “families” of minerals—so the sulphides will be found together, as will the native elements like gold and copper, or the oxides, and so on. It is a teaching collection in a way that no longer exists elsewhere in the building. An eager visitor might spend weeks in here learning, and would emerge at the other end as something of a mineralogist. Underneath the glass cases are ranks of polished drawers locked safely away that contain the systematic collections. Under silica, for example, there is every variety of quartz from brilliantly transparent rock crystal, through yellow citrine or delicately pink rose quartz, to amethyst or red jasper. Some specimens are perfect pointed crystals, others banded agates which somehow recall elaborate confectionery. I last saw the latter on the way to the Moroccan desert, where every bend in the road across the High Atlas comes with a small boy waving agate geodes.
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When the curator, Alan Hart, jangled his special keys to let me in on these secrets, I noticed one of the students edging over to have a peep in the drawer. I could read his expression, at once furtive and riveted: “What! Yet more riches!” Alan showed me one mineral that could not be displayed at all to common view. Proustite has a blood-red colour that fades when exposed to light—a shy creature, indeed. It was not named after the novelist Marcel Proust, though one feels it should have been. These famous, well-formed crystals mined from Copiapo, Chile, some of which would almost cover your hand, have an unreal quality, as if they did not quite belong on this Earth at all. I suppose that since they are a compound of silver, arsenic and sulphur they must also be very poisonous. They thus combine a lethal but hidden beauty; they are of the Earth, but somehow also unearthly. Wordsworth was no friend of geologists, whom he regarded as dull enumerators of facts, but he did write a line that seems quite appropriate to gemstones: “True beauty lies in deep retreats.”

The mineral gallery of the Natural History Museum in about 1920. The systematic arrangement of minerals is preserved today, even though most of the exhibits elsewhere in the Museum have been transformed from their early-twentieth-century state.

Edward Heron-Allen, polymath, novelist, palaeontologist and historian of the violin

Alan Hart then unlocked the drawer housing a special amethyst, safe from causing more trouble at last. The catalogue describes it thus (BM Register 1944, 1): “Quartz (var. Amethyst), faceted, oval (3.5 × 2.5 cm), mounted in silver ring in form of snake, one of which bears two scarabs of amethystine quartz, the other a T in silver, engraved. Locality unknown. Mrs. Mair Jones of London by presentation, January 28, 1944.” Mrs. Mair Jones was the daughter of Edward Heron-Allen, one of the great Museum benefactors until his death in 1943, whose collection of an estimated 25,000,000 specimens formed the backbone for studies of single-celled Foraminifera in the Palaeontology Department. Heron-Allen was an extraordinary polymath, a skilled violinmaker and Persian linguist as well as a world authority on “forams.” He published everything from novels (
Kisses of Fate,
1888), translations (
The Ruba’iyat of Omar Khayyam,
1898), poems (
The Ballades of a Blasé Man,
1891), history (
Selsey Bill, Historic and Prehistoric,
1911) and bibliography (
De Fidiculis Bibliographia, Being an Attempt Towards a Bibliography of the Violin,
1890–94) to natural history (
Barnacles in Nature and Myth,
1928), not to mention shadier material on what would now be called alternative beliefs (
A Manual of Cheirosophy,
1885). One thinks of Dryden’s lines: “A man so various that he seemed to be / Not one, but all mankind’s epitome.” Mrs. Mair Jones included a letter from her father that explains all about the curse of the amethyst. Yellowed with age now, it still lies with the specimen in the locked drawer:

To—whomsoever shall be the future possessor of the Amethyst, these lines are addressed in mourning before he, or she, shall assume the responsibility for owning it.

This stone is trebly accursed and is stained with the blood, and the dishonour of everyone who has ever owned it. It was looted from the treasure of the Temple of the God Indra at Cawnpore during the Indian Mutiny in 1855 and brought to this country by Colonel W. Ferris of the Bengal Cavalry. From the day he possessed it he was unfortunate, and lost both health and money. His son who had it after his death, suffered the most persistent ill-fortune till I accepted the stone from him in 1890. He had given it once to a friend, but the friend shortly afterwards committed suicide and left it back to him by will. From the moment I had it, misfortunes attacked me until I had it bound round with a double headed snake that had been a finger ring of Heydon the Astrologer, looped up with zodiacal plaques and neutralized between Heydon’s Magic Tau and two amethyst scaraboei of Queen Hatasu’s period, bought from Der-el-Bahari (Thebes). It remained thus quietly until 1902, though not only I, but my wife, Professor Ross, W. H. Rider and Mrs Hadden frequently saw in my library the Hindu Yoga, who haunts the stone trying to get it back. He sits on his heels in a corner of the room, digging in the floor with his hands, as if searching for it. In 1902, under protest I gave it to a friend, who was thereupon overwhelmed with every possible disaster. On my return from Egypt in 1903 I found she had returned it to me, and after another great misfortune had fallen on me I threw it into the Regent’s Canal. Three months afterwards it was brought back to me by a Wardour St dealer who had bought it from a dredger. Then I gave it to a friend who was a singer, at her earnest wish. The next time she tried to sing her voice was dead and gone and she has never sung since. I feel that it is exerting a baleful influence over my new born daughter so I am now packing it in seven boxes and depositing it at my bankers, with directions that it is not to see the light again until I have been dead thirty three years. Whoever shall then open it, shall first read this warning, and then do as he pleases with the jewel. My advice to him or her is to cast it into the sea. I am forbidden by the Rosicrucian Oath to do this, or I would have done it long ago.

(Signed) Edward Heron-Allen
October, 1904

I think we get a fair picture of the Heron-Allen style from this letter. The amethyst (see colour plate 15) is an ordinary-looking stone to have had such a “baleful” history. The curses that lie on several famous diamonds might be construed as a way of discouraging thieves, but a humble amethyst would not be worth that kind of trouble. And it really did wait thirty-three years before finding its way to a Museum drawer, which hardly suggests a hoax. I confess to experiencing a measure of nervousness when I handled the jewel, and I am sure that it was pure coincidence that my back seized up most painfully on the following day. There have been requests to wear the amethyst at Museum parties, but Alan Hart keeps it safely out of harm’s way under lock and key. I am told that nobody has yet reported a Hindu Yoga scrabbling at the cupboard to try to retrieve the accursed amethyst and return it to Cawnpore.