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Russian Gemstones Encyclopedia

Vladimir Bukanov. Russian Gemstones Encyclopedia

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

HEMATITE, GROUP: HEMATITE, ILMENITE


HEMATITE group (Hämatit—Hématite— √ематит) (Teophrastus, 315 BCE), from Gk. “aima”, blood, because of its resemblance to dried blood, or aimatites – bloodstone, because of the red color of its powder. Known from antiquity. Here also ilmenite is observed, which produces a mixing row with hematite.

Composition & Properties. Oxide – Fe2O3, trigonal system. Hardness 5-6. Density 5.3. Metal luster. Fragile. It is found as hexagonal plates or flat crystals up to 30 cm. in cross-section. Slightly crooked tabular crystals form sometimes original aggregates, so called iron rose or the Alpine rose. Massive varieties are represented with fine-grained red iron ore and kidneyshaped aggregates – red glass head, blood red hematite or oölitic hematite. The color of hematite crystals is black with bluish tone; cryptiocrystalline aggregates are reddish-brown. Non-transparent to translucent at thin plates. In small tabular aggregates crystals called esmalte, hematite has rainbow iridescence or blueingspiegelstein. It forms pseudomorphs on magnetite – martit; it can also be placed by magnetite – mouchkétovite. Regular oriented inclusions of hematite - iron glance and goethite lead to the aventurescence, asterism and the effect of cat’s-eye in cabochons of apatite, beryl, feldspars, sapphire and other gemstones. The color of such ornamental stones as sealing wax jasper, red marble, heliotrope, jedi-opal, zeolites, feldspar sunstone and cancrinite sunstone is connected with micro-inclusions of hematite. Hematite together with magnetite serves as rock-forming element for ferrous quartzites, which are known as ornamental stone – jaspillite or itabirite. Mixture of hematite with quartz received the trade name Italian lapis.

Deposits. Hematite is formed in the processes of regional metamorphism, contact metasomatism, in hydrothermal veins and in the zones of oxidation. In Russia, in the Subpolar Urals Mts., aggregates of hematite crystals in the shape of iron roses, up to 5 cm. in cross-section, were found in alpine veins of the Pyrtyndyrma deposit, in the upper reaches of the Torgovaya River; Parnuk deposit – in the upper reaches of the Vangyr River, and Maldy-Nyrd deposit, Maldy Nyrd Ridge. At the North Urals, at the Kutim deposit, hematite is represented as red iron ore. In the Middle Urals, hematite crystals up to 12 cm. in cross-section at the Shabry deposit were extracted. At deposits of the Kursk Magnetic Anomaly, hematite is found in the shape of round pebbles. In the Irkutsk Region, large crystals of hematite at the Korshunovskoye deposit are found. In East Transbaikalia, kidney-shaped aggregates of hematite – red glass head at the Berezovskoye deposit, near Nerchinsk, and at the Pad’ Listvyanka deposit, were found. In Kazakhstan, blood-red hematite at the deposits Kishkenesor, Bol’shoy Kitay and Western Qarazhal was extracted. In South Kazakhstan, near Chimkent, a deposit of strawberry quartz is found – it is rose quartz colored from hematite inclusions, which are concentrated near edges and in the upper parts of crystals. In the perpendicular to the longitude of crystals cut plates, taken from the upper parts of crystals, and in cabochons the pseudoasterism in the shape of the three-radial star can be observed.

In Europe, on the western coast of England, at deposits of South Cumbria and Lancashire, ornamental blood-red hematite was extracted. In Romania, hematite crystals up to 5 cm. at the Doganecha deposit were found. In Czech Rep. they were extracted in the iron-ore deposits Gradište and Horní Blatná. In Italy, at the Bacino deposit, near Rio Marina, on the Elba Is., findings of hematite crystals up to 10 cm. in cross-section with bright blueing are known. In the Switzerland and in Austria, wonderful hematite iron roses up to 16 cm. in cross-section were found in alpine veins; they are valuable collection material. Here are tabular crystals up to 30x8 cm. and pseudocubic crystals up to 8 cm. They occur at the Ritterpas deposit, Binn Valley; Valais canton; and at the Cavradi mine, Val Tawetsch, Graubünden canton; also at the Fibbia deposit, Uri canton. In Morocco, globular aggregates hematite – red glass head up to 30x30 cm. from baryte veins occur at Irhoud, near Marakech. On Madagascar, at the Mananara deposit, the size of hematite iron roses reached 15 cm. in cross-section. In Namibia, at the Otjosundu mine, hematite crystals up to 20 cm. in cross-section are known. In South Africa, at the Wessels mine, North Cape Prov., the biggest hematite crystals are extracted; they are up to 30 cm. in cross-section. In China, hematite iron roses up to 3 cm., which were growing on quartz crystals, were found in the Guandong Prov., at the Nanning Shan deposit. In India, they were found in the Jammu and Kashmir State (disputed area), in the region of Skardu. In Japan, at the Gihofudschi deposit, Okajama Pref., lamellate crystals hematites up to 6 cm. in cross-section were found.

In Brazil, gem-quality blood-red hematite in aggregates of red glass head was found at the deposits Urucum and Serra de Mutume, Mato Grosso do Sol State. In Bahia, hematite crystals up to 16 cm. in cross-section at the Brumado deposit were found. In Minas Gerais, hematite crystals up to 12 cm. in cross-section in the Linopolis region were extracted. In the region of Itabira hematite pseudomorphs on crystals of magnetite – martit were found. Near Oro Preto, the biggest hematite iron roses up to 20 cm. in cross-section at the deposit Nova Era were found. The best of them were evaluated up to $6,000 at the gem-fair in Tucson, the U.S.A. In the Alaska State, on the Prince of Wales Is., hematite iron roses from tabular crystals up to 5 cm. long were found in cavity of garnet-pyroxene skarns. In Colorado, at the Pike’s Peak deposit, El Paso Co., hematite pseudomorphs on siderite crystals was found. In Mexico, at the Cerro de Mercado deposit, Durango State, hematite forms pseudomorphs on crystals of magnetite – martit up to 10 cm. in size.

Ornamental rocks. Jaspillite is ornamental ferrous quartzite, which consists of fine-grained hematite, magnetite and quartz; it usually has fine-stripped and even picture texture. It is extracted in Russia as additional material during the working out of iron-ore quartzites at the Mikhailovskiy mine, Kursk Region, and on the Kola Penin. – at the Olenegorskoye deposit; in the Ukraine – at the Krivorozhskoye deposit; in Kazakhstan – at the Zapadnyy Karazhal deposit. In the U.S.A. ornamental jaspillite is extracted in the Michigan State. The similar ornamental stone is itabirite from Brazil, which is called so on the place of finding near Itabira Mts., Minas Gerais State. Also there, near Belo Horizonte, at an iron-ore deposit, a vein of massive iris rainbow hematite was found.

Synonyms. Hematite – Black diamond | Alaska black diamond | Eisenglimmer, Germ. | Ernglas, Germ. | Glaskopf, Germ. | Haematolith | Hematokonite | Iridescent hematite | Specular iron | Jaspillite, from Engl. “jasper”, on the similarity | ~ iron: glance ~, red glance ~ | Kidney iron | Martit, after the god of war Mars | ~ ore: iron ~, glance iron ~, red iron ~, rhombohedral iron ~, kidney ~, mirror ~, pencil ~, red ~ | Red Persian | Sanguine, from Lat. “sanguis” – blood | Specularite, from Gk. “spekula” – contemplation | ~ stone: glance iron ~, red iron ~, kidney ~, lustrous ~.

Cut Gems. As an ornamental stone, hematite was well-known in the ancient world. In Ancient Rome, it was evaluated at the silver level. Cameo and intaglio as well as other jewelries with blood-red hematite have been in fashion from time to time since the epoch of the Renaissance. In the gem collection of the State Hermitage, SPb., there are cylinder stamps from the Sumer Kingdom and carved miniatures from Iran, made on hematite. Snake-legged demon is carved on one cameo from Pantikapei, 3th cent., 2.3x1.4 cm.; Egyptian gods, Persephone and Nemesis – on another one from North Prichernomoria (Black Sea Region), 2-3ss cent., 2.5 cm. in cross-section. Ilmenite is cut as hematite.

Hematite is cut in cabochon and as flat insets. Large gems with brilliant faceting are made from it as well as small ones with rose faceting. Hematite balls imitate black pearls; beads, necklaces, bracelets and crosses are made from them. Jewelers use blood-red hematite as a polishing stone for gold items.

Legends. The special popularity of hematite among astrologers as a talisman is connected with the belief, that the force of the Mars planet is included in it. They say it gives to those, who were born under the zodiac sign of Scorpio, the ability to influence at the other people. It is a lucky stone of those, who were born under the zodiac sign of Cancer. As an amulet, it protects warriors in the battle and keeps them from splashes of anxiety. It was used as a mean to stop bleeding and to heal wounds. In the U.S.A. hematite is the official symbol of Alabama.

Synthesis. Hematite is received with the method of pressing from iron oxide powder for manufacturing of bijouterie. It differs from hematite with the presence of magnetic effect and higher hardness – 6.5 with density 4.8. For the imitation of almandine garnet sometimes hematite garnet is used. It is artificial product with garnet structure. Its composition: Fe3AlO12. Hardness 7. Density 4.2. Metal luster. Dark red color. It has been producing in Zimbabwe since 1976.

Similar Gemstones & Imitations. Hematite looks like wolframite, ilmenite, cinnabar, cuprite and magnetite. From cinnabar it differs with the absence of cohesion, from cuprite – with the less hardness, from the others – with the red drawn line. The widespread imitation of hematite is received by means rosa-cut steel – hematine. Previous times psilomelane was used mainly for it, and under the name iserine (iserite) usually one of ferrous minerals was hidden: hercynite, titanomagnetite or ilmenite.

Ilmenite (Ilmenit—Ilménite—»льменит) (Kupffer, A.T. 1827), after its discovery locality, Ilmeny Mts., South Urals, Russia. Oxide – FeTiO3, trigonal system. Hardness 5-6. Density 4.6-4.8. Metal luster. Cleavage – none. Fragile. It is found in magmatic rocks, pegmatites and at the placers as flat, non-transparent black crystals. It looks like hematite, for the imitation of which it is used. It differs from hematite with the black drawn line. As inclusions it can be observed in hematite, magnetite, quartz, labradorite and some other gemstones.

In Russia, on the Kola Penin., at the deposit Poachvumchorr, Khibiny, the size of ilmenite crystals reached 1 m. in cross-section. In the South Urals, in alkali-pegmatites in the Ilmeny Mts. and in the Middle Urals, Vishnevye Mts., ilmenite crystals reach 25x20x18 cm. in size, and 60 kg. they were found. In the Subpolar Urals Mts., in alpine veins of the deposits Dodo, Central Patok and others, ilmenite crystals up to 5 cm. in cross-section as inclusions in rock crystal were found. Besides, rutile in the shape of star-aggregates is developing over them. In Norway, ilmenite crystals had the size up to 12 cm., weight 7 kg. at the Kragerø deposit; at Arendal and at Iveland deposits their size in a cross-section reached 1 m. In Switzerland, in alpine veins a ilmenite crystals form iron roses up to 1 cm. at Maderanertal deposit, Uri canton. In India, in the Jammu and Kashmir State (disputed area), they reach 2 cm. in cross-section. In Canada, ilmenite crystals up to 30 kg were found at the Faraday deposit, Bancroft region, Ontario; and also in Girardville – up to 15 cm. in a cross-section. In Brazil, at rock crystal deposits, crystals of quartz are found with inclusions of ilmenite and hematite plates, on which star-aggregates of rutile are developing.

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