Mineralogy

E-book.
Lahore, Pakistan
©2019 ASAS
(A Roads and Religions Research Initiative e-publication)

New archaeological and geological discoveries during last few decades open ways to reinterpret certain historical accounts in Abrahamic sacred texts. One such passage is the narrative of ants and Solomon in Quran. New dimensions opened by science and archaeological discoveries make it possible to look into the matter from a totally different perspective. New researches confirm the view presented by very few in past that Namal (ants) were people involved in collecting ant-gold or placer from sand, alluvial deposits and gravel in and around auriferous sessional streams beds (wadis) in different areas between Palestine and Saba from early Bronze Age to present. Moreover after a careful examination of the available evidence, it could be suggested that Wad-al-Naml and the gold river of the Greek travellers could be one and the same  geographical feature.
پہلے ہزاریے ق م میں جزیرہ نمائے عرب  کے موسمی دریاؤں کی ریت اور مٹی میں سے سونا اکٹھا کرنے کے اثریاتی شواہد کی دستیابی نے اس عام خیال کے برعکس کہ  حضرت سلیمان علیہ السلام کے قومِ سبا کی طرف لشکر کشی کے دوران واد النمل میں آپ کی  چیونٹیوں سے بات چیت ہوئی آپ کے دراصل ایک ایسی قوم کے پاس سے گزرنے کے ثبوت فراہم کئے ہیں جوسونے کے ذرّات کی حامل موسمی وادیوں سے ذھب النمل یعنی ant-gold جمع کرتی تھی۔ سونا جمع کرنے کے عمل میں چیونٹیوں سے مدد لینے، چیونٹیوں کی طرح کھدائی کرکے اور چن کر سونے کے ذرات جمع کرنے اور چیونٹیوں کے بلوں اور گھروندوں کی طرح کے آثار چھوڑنے کی وجہ سے ذھب النمل جمع کرنے والوں کو بھی نمل ہی کہا گیا۔ اس مضمون میں ایک نئے زاویہء تحقیق سے اس سارے معاملے کا ایک جائزہ پیش کیا گیا ہے۔ اسی طرح ایک جامع تجزیے کے بعد تجویز کیا گیا ہے کہ واد النمل اور یونانیوں کا سونے کا دریا ایک ہی مقام ہو سکتےہیں۔

The chemical composition of tourmaline has been used as a host environment register as well as a potential exploration tool for mineral deposits. In this study, the textural and chemical composition of tourmalines associated with Zn-Pb mineralizations around the Murguía diapir (Basque Cantabrian Basin, N Spain) are examined to verify if they record the mineralizing events in the area. Petrographically, tourmalines have been differentiated between inherited and authigenic. Colorless authigenic tourmalines are present as halos partially around green and pleochroic detrital grains or as individual crystals. Inherited and authigenic tourmalines are also chemically distinct. Authigenic tourmalines show different X-site occupancies, a Mg/(Mg+Fe) ratio above 0.77, and are aluminum rich and plot to the right of the povondraite-oxidravite join, above the schorl-dravite join. Inherited tourmalines plot within the alkaline (Na+K) group field, and have a Mg/(Mg+Fe) ratio below 0.77. These data suggest that authigenic tourmalines grew under reducing conditions, compatible with the hydrothermal event responsible for the ore deposition and caprock formation during the diapir ascent. Tourmaline. Salt diapir. Zn-Pb deposits. Basque Cantabrian Basin.

V oblasti Černé v Pošumaví jsou známé čtyři lithné pegmatity (Bližná I, Bližná II, Černá I, Černá II). Všechna zmiňovaná tělesa náleží k elbaitovému subtypu pegmatitů, v nichž je hlavním nosičem Li elbait. Všechna tělesa se kromě vizuální podobnosti podobají i chemismem minerálů v nich obsažených. Zdrojová tavenina pro všechna tělesa má tedy pravděpodobně stejný původ. Markantní odlišnost mineralogie tělesa Bližná I je způsobená silnou kontaminací Ca z mramoru, který je pegmatitem penetrován.
Pegmatit Černá I má vyvinutých celkem pět strukturních jednotek (biotitickou, granitickou, blokovou, grafickou a blokovou křemennou). Vývoj chemismu turmalínu sleduje trend Ca-dravit-skoryl → skoryl → Mn-Li-skoryl → Fe-tsilaisit-elbait → tsilaisit-elbait → elbait → Ca-fluor-elbait. Trend vývoje turmalínu blokové jednotky (skoryl → Ca-fluor-elbait) pegmatitu Černá I a dalších těles lithných pegmatitů více, či méně, obohacených Mn je totožný a je možné generalizovat ho na trend skoryl → tsilaisit/elbait → elbait → liddicoatit. Tsilaisit/elbaitový člen evoluční řady má v případě dostatku Mn v tavenině tendenci posunu směrem k tsilaisitovému členu za neustálého snižování obsahu Fe v turmalínu. Následně dochází k snižování obsahu Mn při konstantním Fe = 0 a substituci za LiAl. Primární dravit v kontaktní zóně pegmatitu je alterován Ca-Fe-Mg bohatými fluidy na sekundární dravit obohacený o zmíněné prvky.

Large-ion lithophile elements (LILE)-enriched chromium titanates of the magnetoplumbite (AM 12 O 19) and crichtonite (ABC 18 T 2 O 38) groups have been recognized as abundant inclusions in orthopyroxene grains in a mantle-derived xenolith from the Udachnaya-East kimberlite pipe, Daldyn field, Siberian craton. The studied xenolith consists of three parts: an orthopyroxenite, a garnet clino-pyroxenite, and a garnet-orthopyroxene intermediate domain between the two. Within the host enstatite (Mg# 92.6) in the orthopyroxenitic part of the sample titanate inclusions are associated with Cr-spinel, diopside, rutile, Mg-Cr-ilmenite, and pentlandite. Crichtonite-group minerals also occur as acicular inclusions in pyrope grains of the intermediate domain adjacent to the orthopyroxenite, as well as in interstitial to enstatite oxide intergrowths together with Cr-spinel, rutile, and ilmenite. Yimengite-hawthorneite inclusions in enstatite contain (wt%) 3.72-8.04 BaO, 2.05-3.43 K 2 O, and 0.06-0.48 CaO. Their composition is transitional between yimengite and hawthorneite end-members with most grains exhibiting K-dominant chemistry. A distinct feature of the studied yimengite-hawthorneite minerals is a high content of Al 2 O 3 (5.74-7.69 wt%). Crichtonite-group minerals vary in compositions depending on the occurrence in the xenolith: inclusions in enstatite are moderate-high in TiO 2 (62.9-67.1 wt%), moderately Cr-rich (12.6-14.0 wt% Cr 2 O 3), Ba-or K-specific in the A site, and contain low ZrO 2 (0.05-1.72 wt%), whereas inclusions in pyrope are moderate in TiO 2 (61.7-63.3 wt% TiO 2), relatively low in Cr (8.98-9.62 wt% Cr 2 O 3), K-dominant in the A site, and are Zr-enriched (4.64-4.71 wt% ZrO 2). Crichtonite-group minerals in polymineralic oxide intergrowths show highly diverse compositions even within individual aggregates, where they are chemically dominated by Ba, Ca, and Sr. P-T estimates indicate the orthopyroxenite to have equilibrated at ~800 °C and 35 kbar. Preferentially oriented lamellae of enstatite-hosted Cr-spinel and diopside, as well as pyrope, diopside, and Cr-spinel grains developed around enstatite crystals, are interpreted to have been exsolved from the high-T Ca-Al-Cr-enriched orthopyroxene precursor. The exotic titanate compositions and observed textural relationships between inclusions in enstatite imply that the studied orthopyroxenite has undergone metasomatic processing by a mobile percolating agent afterward; this highly evolved melt/ fluid was enriched in Ba, K, HFSE, and other incompatible elements. The infiltration of the metaso-matizing liquid occurred through interstices and vulnerable zones of enstatite grains and manifested in the crystallization of titanate inclusions. It is assumed that Cr-spinel lamellae served as seeds for their nucleation and growth. The prominent textural and chemical inhomogeneity of the interstitial oxide intergrowths is either a consequence of the metasomatic oxide crystallization shortly prior to the kimberlite magma eruption or arose from the intensive modification of preexisting oxide clusters by the kimberlite melt during the Udachnaya emplacement. Our new data provide implications for the metasomatic treatment of orthopyroxenites in the subcontinental lithospheric mantle from the view of exotic titanate occurrences.

Phyllites from the Dewon–Pokrzywna deposit in the Opava Mts., SW Po land, were investigated by XRD (Rietveld method), XRF, EPMA, SEM, and ATR-FTIR from the perspective of their potential usage as a buffer and/or backfill material in a geological repository of radioactive waste. Organic matter dispersed in the phyllite matrix was analyzed by GC-MS. Fine-grained Mg-Fe-muscovite (13 to 29 wt.%), Fe-ripidolite (10 to 25 wt.%), detrital quartz (20 to 46 wt.%), and albite (7 to 28 wt.%) ±microcline, illite or illite/smectite, and kaolinite are major minerals in phyllite samples. The chlorite/muscovite ratio ranges from 0.65 to 1.1. Mg-annite inherited from the precursor rock is a minor constituent. Detrital ilmenite is a dominant accessory
mineral. Ancylite-(Ce) occurs in quartz-cal cite-ripidolite veins. Two types of phyllite have been distinguished based on the proportion of phyllosilicates to silt fraction: argillaceous (47 to 55 wt.% phyllosilicates) and silt-rich (28 wt.% phyllosilicates). Argillaceous phyllite shows elevated content of alumina and mod er ate concentration of silica. It is highly enriched in Fe compared to phyllites from other localities worldwide. The BET specific surface area of argillaceous phyllite ranges from 1.73 to
3.64 m2/g. Whole-rock chemical composition, mineral assemblages, chlorite geothermometry, and the occurrence of aliphatic hydrocarbons suggest that argillaceous phyllite originated from a pelagic pelite protolith under low-temperature
(260–370°C) greenschist to subgreenschist facies conditions. Per sis tent biomarkers are indicative of bac te rial degradation of planktonic organic matter suspended in a high water column. Enrichment in Fe-rich chlorite and Mg,Fe-muscovite, low vol -
ume of interconnected pores with dominant mesopores suggest that argillaceous phyllite from the Dewon–Pokrzywna deposit is a potential candidate for a buffer and/or backfill material.

A field trail was conducted to test the effect of volcanic ash application on some soil properties and potato crop grown in The
Res. Station, Fac. of Agric., Cairo Univ. located at Wadi El-Natron region, El-Behira Governorate, Egypt. The results show that iron
oxides, silica and alumina represented 91.5, 6.0 and 2.5% of the total amorphous materials, respectively. Molar ratio of SiO2
/Al2O3
of
volcanic ash was 2.08. Light minerals are mainly composed of feldspars and quartz and having a specific gravity less than 2.85 g/cm3
.
Opaque, pyroxenes and amphibole heavy minerals represented about 70% of the total heavy minerals. kaolinite predominated the clay
minerals followed by montmorillonite, while cholorite was detected in trace amount. Zeolite of volcanic ash has high alumina content
and low Si/Al ratio (less than 4) which is considered a hydrophilic soil conditioner. The texture of volcanic ash is considered coarse with
bulk density value of 1.36 g/cm3
and total porosity value of 41.25% (65.90 % macro-pores and 34.10 % micro-pores). The electric
conductivity (EC) of volcanic ash was low value (0.45) and reaction value (pH) of 5.9. There was no symptom of nutrients deficit in
potato leaves or tuber as a result of using volcanic ash. Therefore, volcanic ash might be used safely to increase soil fertility and improve
soil properties as soil conditioner. Moreover soil productivity might be augmented by applying volcanic ash to the soil
Keywords: Volcanic ash, soil fertility, soil conditioner, light and heavy minerals, potato crop.

The Takab meta-ultramafic rocks of northwestern Iran crop out in association with a variety of metamorphic rocks and they can be divided into three types on the basis of dominant mineral assemblage and degree of serpentinization: metaperidotites, talc-serpentine rocks and serpentinites. The peridotite protoliths were mainly spinel-harzburgites and-dunites. The talc-serpentine rocks formed under low-grade conditions and their dominant mineral assemblage is lizardite/chrysotile + talc + calcite/dolomite. Pseudomorphic textures after olivine and pyroxene are typical. Later, lower amphibolite-facies metamorphism produced antigorite, clinochlore and tremolite. Late alteration, assisted by local shearing, produced more antigorite and late lizardite in the metaperidotites. The mineral chemistry of the serpentine polymorphs is variable. Compositions of coexisting spinel and olivine point to an ophiolitic origin. Thermometric estimates from co-existing relict olivine, pyroxenes and spinel are in the range 1000À1200ºC; clinopyroxene barometry yields a pressure of 24Ô2.7 kbar for the mantle conditions. Exhumation and hydration followed, and the stability of lizardite/chrysotile constrains the T and X CO 2 to <280ºC and <0.002, respectively. Subsequent prograde regional metamorphism took place in an orogenic setting, reaching peak temperatures in the range 410À540ºC at X CO 2 >0.1. A Neoproterozoic-Early Cambrian age for the Takab protoliths is suggested on the basis of correlations with the Central Iran Zone. The strips of ultramafic rock in the Takab complex can be attributed to lithospheric remnants of the Proto-Tethyan ocean which closed during the Pan-African orogeny.