"Fred Bramley, was ill, Citrine took on a much wider role from the start. In time, he would transform it into a coherent and effective lobbying organisation for a growing movement. He acted enthusiastically as General Secretary during the General Strike of 1926 and was confirmed in that position after it, without opposition, at the Trades Union Congress of September 1926. The defeat of the general strike proved a watershed for the trade unions, persuading most General Council leaders to abandon their previous syndicalist philosophy. With other leading figures, such as Ernest Bevin (1881-1951), Citrine helped change the face of"
"Ametrine Ametrine, also known as trystine or by its trade name as bolivianite, is a naturally occurring variety of quartz. It is a mixture of amethyst and citrine with zones of purple and yellow or orange. Almost all commercially available ametrine is mined only in Bolivia. The colour of the zones visible within ametrine are due to differing oxidation states of iron within the crystal. The different oxidation states occur due to there being a temperature gradient across the crystal during its formation. Artificial ametrine can be created by differential heat treatment of amethyst. Legend has it that ametrine was"
"Nephrite Nephrite is a variety of the calcium, magnesium, and iron-rich amphibole minerals tremolite or actinolite (aggregates of which also make up one form of asbestos). The chemical formula for nephrite is Ca(Mg, Fe)SiO(OH). It is one of two different mineral species called jade. The other mineral species known as jade is jadeite, which is a variety of pyroxene. While nephrite jade possesses mainly grays and greens (and occasionally yellows, browns or whites), jadeite jade, which is rarer, can also contain blacks, reds, pinks and violets. Nephrite jade is an ornamental stone used in carvings, beads, or cabochon cut gemstones."
"Anthophyllite Anthophyllite is an amphibole mineral: ☐MgMgSiO(OH) (☐ is for a vacancy, a point defect in the crystal structure), magnesium iron inosilicate hydroxide. Anthophyllite is polymorphic with cummingtonite. Some forms of anthophyllite are lamellar or fibrous and are classed as asbestos. The name is derived from the Latin word ""anthophyllum"", meaning ""clove"", an allusion to the most common color of the mineral. Anthophylite is the product of metamorphism of magnesium-rich rocks, especially ultrabasic igneous rocks and impure dolomitic shales. It also forms as a retrograde product rimming relict orthopyroxenes and olivine, and as an accessory mineral in cordierite-bearing gneisses and"
"nephrite, one of the two types of jade (the other being jadeite, a variety of pyroxene). Another gem variety is the chatoyant form known as ""cat's-eye actinolite"". This stone is translucent to opaque, and green to yellowish green color. This variety has had the misnomer ""jade cat's-eye"". Transparent actinolite is rare and is faceted for gem collectors. Major sources for these forms of actinolite are Taiwan and Canada. Other sources are Madagascar, Tanzania, and the United States. Actinolite Actinolite is an amphibole silicate mineral with the chemical formula . The name ""actinolite"" is derived from the Greek word ""aktis"" (),"
"first introduced to Europe by a conquistador's gifts to the Spanish Queen, after he received a mine in Bolivia as a dowry when he married a princess from the native Ayoreos tribe. Most ametrine in the low price segment can be assumed to stem from synthetic material. Since 1994, a Russian laboratory has perfected the industrial production of bicolored quartz crystals that are later irradiated to bring out the typical ametrine colors. Green-yellow or golden-blue ametrine does not exist naturally. Ametrine Ametrine, also known as trystine or by its trade name as bolivianite, is a naturally occurring variety of quartz."
"minerals containing Pb, Cu, Fe, and Zn are also present. The minerals contained in this abnormal sequence contain Pb, Cu, SO , and CO and they may occur in the same minerals. The element Antimony is a very rare element that is exhibited in mammothite but also in the mineral tetrahedrite, which is seen having small crystals that are attached to pyrite crystals. In Laurium, Attika, Greece, the mammothite exists as small euhedral crystals and also as microscopic rock cavities lined with projecting crystals within the slags. The associated minerals here are cerussite,phosgenite and matlockite. Mammothite is a cerulean blue"
"Apatite, magnetite, and zircon, all in small but frequently perfect crystals, are almost universal minerals of the quartz-porphyries. The ground-mass is finely crystalline and to the unaided eye has usually a dull aspect resembling common earthenware; it is grey, green, reddish or white. Often it is streaked or banded by flow during cooling, but as a rule these rocks are not vesicular. Two main types may be recognized by means of the microscope; the felsitic and the microcrystalline. In the former the ingredients are so fine-grained that in the thinnest slices they cannot be determined by means of the microscope."
"stone. Chatoyant minerals display luminous bands, which appear to move as the specimen is rotated. Such minerals are composed of parallel fibers (or contain fibrous voids or inclusions), which reflect light into a direction perpendicular to their orientation, thus forming narrow bands of light. The most famous examples are tiger's eye and cymophane, but the effect may also occur in other minerals such as aquamarine, moonstone and tourmaline. Color change is most commonly found in alexandrite, a variety of chrysoberyl gemstones. Other gems also occur in color-change varieties, including (but not limited to) sapphire, garnet, spinel. Alexandrite displays a color"
"Sapphirine Sapphirine is a rare mineral, a silicate of magnesium and aluminium with the chemical formula (Mg,Al)(Al,Si)O (with iron as a major impurity). Named for its sapphire-like colour, sapphirine is primarily of interest to researchers and collectors: well-formed crystals are treasured and occasionally cut into gemstones. Sapphirine has also been synthesized for experimental purposes via a hydrothermal process. Typical colours range from light to dark sapphire blue, bluish to brownish green, green, and bluish or greenish gray to black; less common colours include yellow, pale red, and pink to purplish pink. Sapphirine is relatively hard (7.5 on Mohs scale), usually"
"Anhydrite Anhydrite is a mineral—anhydrous calcium sulfate, CaSO. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium (baryte) and strontium (celestine) sulfates, as might be expected from the chemical formulas. Distinctly developed crystals are somewhat rare, the mineral usually presenting the form of cleavage masses. The Mohs hardness is 3.5 and the specific gravity is 2.9. The color is white, sometimes greyish, bluish, or purple. On the best developed of the three cleavages, the lustre is pearly; on other surfaces it"
"Cymrite Cymrite is a silicate mineral with the chemical formula BaAlSi(O,OH)·HO. The mineral is named for Cymru, which is the Welsh word for Wales. Cymrite, with perfect cleavage and a monoclinic crystalline system, falls in the silicate group. Silicates are formed of Silicon and Oxygen bonding together to form tetrahedra. The symmetry of Cymrite is classified as having a mirror plane. It has a moderate relief, meaning the contrast between the mineral and the epoxy of a thin section makes cymrite easily visible. The birefringence of the mineral is 0.01. Cymrite, being monoclinic is anisotropic with two optic axes. Cymrite"
"only in ruby. Sapphire and ruby are both varieties of the same mineral; corundum. Some minerals may replace other existing minerals while preserving the original's habit: this process is called pseudomorphous replacement. A classic example is tiger's eye quartz, crocidolite asbestos replaced by silica. While quartz typically forms ""prismatic"" (elongate, prism-like) crystals, in tiger's eye the original ""fibrous"" habit of crocidolite is preserved. The names of crystal habits are derived from: Predominant crystal faces (prism – prismatic, pyramid – pyramidal and pinacoid – platy). Crystal forms (cubic, octahedral, dodecahedral). Aggregation of crystals or aggregates (fibrous, botryoidal, radiating, massive). Crystal appearance"
"Dome Rock Mountains of La Paz County, Arizona, Stockdale, Riley County, Kansas; Cortlandt, New York; and Clay County, North Carolina. Sapphirine Sapphirine is a rare mineral, a silicate of magnesium and aluminium with the chemical formula (Mg,Al)(Al,Si)O (with iron as a major impurity). Named for its sapphire-like colour, sapphirine is primarily of interest to researchers and collectors: well-formed crystals are treasured and occasionally cut into gemstones. Sapphirine has also been synthesized for experimental purposes via a hydrothermal process. Typical colours range from light to dark sapphire blue, bluish to brownish green, green, and bluish or greenish gray to black; less"
"amethyst, citrine, and the other varieties of crystalline quartz. Other members of the cryptocrystalline silica family include agate, carnelian, and onyx. Unlike many non-transparent silica minerals, it is the color of chrysoprase, rather than any pattern of markings, that makes it desirable. The word chrysoprase comes from the Greek χρυσός ""chrysos"" meaning 'gold' and πράσινον ""prasinon"", meaning 'green'. Unlike emerald which owes its green color to the presence of chromium, the color of chrysoprase is due to trace amounts of nickel compounds in the form of very small inclusions. The nickel reportedly occurs as different silicates, like kerolite or pimelite"
"Actinolite Actinolite is an amphibole silicate mineral with the chemical formula . The name ""actinolite"" is derived from the Greek word ""aktis"" (), meaning ""beam"" or ""ray"", because of the mineral's fibrous nature. (This word is also the origin of the name of the chemical element actinium.) Actinolite is an intermediate member in a solid-solution series between magnesium-rich tremolite, , and iron-rich ferro-actinolite, . Mg and Fe ions can be freely exchanged in the crystal structure. Like tremolite, asbestiform actinolite is regulated as asbestos. Actinolite is commonly found in metamorphic rocks, such as contact aureoles surrounding cooled intrusive igneous rocks."
"crystals.) Cryptohalite has the cubic (isometric) crystal structure and corresponds to the alpha form. Both minerals have the chemical formula (NH)SiF. The halides of form ""ABX"" fall into two groups: hieratite and malladrite. The hieratite group is isometric whereas the malladrite is hexagonal. The (SiF) is octahedral—one fluorine atom at each vertex. In bararite, the (NH)’s are trigonally coordinated. They all appear at sites of C (3m) symmetry. The (NH) has 12 fluorine neighbors, which form four triangles. Three of these triangles are isosceles. These triangles themselves form a triangle—around the 3-fold axis containing the nitrogen atom. One triangle is"
"Examples of such minerals are malachite (green) and azurite (blue). In contrast, allochromatic elements in minerals are present in trace amounts as impurities. An example of such a mineral would be the ruby and sapphire varieties of the mineral corundum. The colours of pseudochromatic minerals are the result of interference of light waves. Examples include labradorite and bornite. In addition to simple body colour, minerals can have various other distinctive optical properties, such as play of colours, asterism, chatoyancy, iridescence, tarnish, and pleochroism. Several of these properties involve variability in colour. Play of colour, such as in opal, results in"
"Superior region of Minnesota, Wisconsin and Michigan. Amethyst is relatively common in the Canadian provinces of Ontario and Nova Scotia. The largest amethyst mine in North America is located in Thunder Bay, Ontario. Up until the 18th century, amethyst was included in the cardinal, or most valuable, gemstones (along with diamond, sapphire, ruby, and emerald). However, since the discovery of extensive deposits in locations such as Brazil, it has lost most of its value. Collectors look for depth of color, possibly with red flashes if cut conventionally. As amethyst is readily available in large structures the value of the gem"
"""lavender"" in a basic purple color chart. The color amethyst is a moderate, transparent violet. Its name is derived from the stone amethyst, a form of quartz. The first recorded use of ""amethyst"" as a color name in English was in 1572. Though the color of natural amethyst varies from purple to yellow, the amethyst color referred to here is the moderate purple color most commonly associated with amethyst stones. There is disagreement as to the cause of the purple color of the amethyst stone. Some believe that the color is due to the presence of manganese, while others have"
"lorandite, baryte and getchellite at the Carlin mine and with lorandite, baryte, pyrite and marcasite in the Lanmuchang. Christite Christite is a mineral with the chemical formula TlHgAsS. It is named after Dr. Charles L. Christ, a member of the U.S. Geological Survey. It usually comes in a crimson red or bright orange color. It has a density of 6.2 and has a rating between 1 and 2 on Mohs Hardness Scale. Christite has an adamantine luster and leaves behind an orange streak. Its crystal system is monoclinic with possible crystal classes of twofold symmetry, mirror plane symmetry, and twofold"
"olivine is a 310 carat (62 g) specimen in the Smithsonian Museum in Washington, D.C. Peridot olivine is the birthstone for the month of August. Peridot Peridot ( or ) is gem-quality olivine, which is a silicate mineral with the formula of (Mg, Fe)SiO. As peridot is the magnesium-rich variety of olivine (forsterite), the formula approaches MgSiO. The origin of the name ""peridot"" is uncertain. The ""Oxford English Dictionary"" suggests an alteration of Anglo–Norman ""pedoretés"" (classical Latin ""pæderot""-), a kind of opal, rather than the Arabic word ""faridat"", meaning ""gem"". The Middle English Dictionary's entry on ""peridot"" includes several variations"
"Beryl Beryl ( ) is a mineral composed of beryllium aluminium cyclosilicate with the chemical formula BeAlSiO. Well-known varieties of beryl include emerald and aquamarine. Naturally occurring, hexagonal crystals of beryl can be up to several meters in size, but terminated crystals are relatively rare. Pure beryl is colorless, but it is frequently tinted by impurities; possible colors are green, blue, yellow, red (the rarest), and white. Beryl is also an ore source of beryllium. The name ""beryl"" is derived (via , , and ) from Greek βήρυλλος ""beryllos"" which referred to a ""precious blue-green color-of-sea-water stone""; akin to Prakrit"
"been found in Russia, Austria, the Czech Republic, and Hungary. It was named from the Greek ""meli"" ""honey"", in allusion to its color. It is found associated with lignite and is assumed to be formed from plant material with aluminium derived from clay. Mellite Mellite, also called honeystone, is an unusual mineral being also an organic chemical. Chemically identified as an aluminium salt of mellitic acid; that is, aluminium benzene hexacarboxylate hydrate, with the chemical formula AlC(COO)·16HO. It is a translucent honey-coloured crystal which can be polished and faceted to form striking gemstones. It crystallizes in the tetragonal system and"
"Christite Christite is a mineral with the chemical formula TlHgAsS. It is named after Dr. Charles L. Christ, a member of the U.S. Geological Survey. It usually comes in a crimson red or bright orange color. It has a density of 6.2 and has a rating between 1 and 2 on Mohs Hardness Scale. Christite has an adamantine luster and leaves behind an orange streak. Its crystal system is monoclinic with possible crystal classes of twofold symmetry, mirror plane symmetry, and twofold with a mirror plane. This means it can have radial symmetry, mirror plane symmetry, or mirror plane symmetry"
"the distinctively coloured pinkish purple mineral erythrite Co(AsO)·8HO and nickel forms annabergite Ni(AsO)·8HO. Köttigite forms series with all three of these minerals and they are all members of the vivianite group. The Vivianite Group is a group of monoclinic phosphates and arsenates with divalent cations. The group members are annabergite, arupite, babanekite, baricite, erythrite, hornesite, kottingite, manganhornesite, pakhomovskyite, parasymplesite and vivianite. Köttigite belongs to the monoclinic crystal system, so it has two crystal axes, a and c, inclined to each other at angle β, and a third axis, the b axis, at right angles to both a and c. It"
"they help to define the limits of what constitutes a mineral proper. The formal Nickel (1995) definition explicitly mentioned crystallinity as a key to defining a substance as a mineral. A 2011 article defined icosahedrite, an aluminium-iron-copper alloy as mineral; named for its unique natural icosahedral symmetry, it is a quasicrystal. Unlike a true crystal, quasicrystals are ordered but not periodic. Minerals are not equivalent to rocks. A rock is an aggregate of one or more minerals or mineraloids. Some rocks, such as limestone or quartzite, are composed primarily of one mineral—calcite or aragonite in the case of limestone, and"
"The name is for the Andes due to its abundance in the andesite lavas in those mountains. In the early 2000s, red and green gemstones began to be marketed under the name of 'andesine'. After some controversy, these gemstones were subsequently discovered to have been artificially-colored. Andesine occurs in intermediate igneous rocks such as diorite, syenite and andesite. It characteristically occurs in metamorphic rocks of granulite to amphibolite facies commonly exhibiting antiperthite texture. It also occurs as detrital grains in sedimentary rocks. It is commonly associated with quartz, potassium feldspar, biotite, hornblende and magnetite. Andesine Andesine is a silicate mineral,"
"Celestine (mineral) Celestine or celestite is a mineral consisting of strontium sulfate (SrSO). The mineral is named for its occasional delicate blue color. Celestine and the carbonate mineral strontianite are the principal sources of the element strontium, commonly used in fireworks and in various metal alloys. Celestine derives its name from the Latin word ""caelestis"" meaning celestial, which in turn is derived from the Latin word ""caelum"" meaning sky or heaven. Celestine occurs as crystals, and also in compact massive and fibrous forms. It is mostly found in sedimentary rocks, often associated with the minerals gypsum, anhydrite, and halite. The"
"Dyscrasite The silver antimonide mineral dyscrasite has the chemical formula AgSb. It is an opaque, silver white, metallic mineral which crystallizes in the orthorhombic crystal system. It forms pyramidal crystals up to and can also form cylindrical and prismatic crystals. Dyscrasite is a metal ore and is opaque. In reflected light, however, it demonstrates weak anisotropism. Dyscrasite’s color under plane polarized light is most likely dark grey/black. When spun on a rotatable stage of a microscope (under plane polarized light), dyscrasite’s color should slightly change shades. This property is called pleochroism. Dyscrasite exhibits very weak reflected light pleochroism. Dyscrasite belongs"
"Two polymorphs of forsterite are known: wadsleyite (also orthorhombic) and ringwoodite (isometric). Both are mainly known from meteorites. Peridot is the gemstone variety of forsterite olivine. Pure forsterite is composed of magnesium, oxygen and silicon. The chemical formula is MgSiO. Forsterite, fayalite (FeSiO) and tephroite (MnSiO) are the end-members of the olivine solid solution series; other elements such as Ni and Ca substitute for Fe and Mg in olivine, but only in minor proportions in natural occurrences. Other minerals such as monticellite (CaMgSiO), an uncommon calcium-rich mineral, share the olivine structure, but solid solution between olivine and these other minerals"
"Chrysoberyl The mineral or gemstone chrysoberyl is an aluminate of beryllium with the formula BeAlO. The name chrysoberyl is derived from the Greek words χρυσός ""chrysos"" and βήρυλλος ""beryllos"", meaning ""a gold-white spar"". Despite the similarity of their names, chrysoberyl and beryl are two completely different gemstones, although they both contain beryllium. Chrysoberyl is the third-hardest frequently encountered natural gemstone and lies at 8.5 on the Mohs scale of mineral hardness, between corundum (9) and topaz (8). An interesting feature of its crystals are the cyclic twins called ""trillings"". These twinned crystals have a hexagonal appearance, but are the result"
"Agate Agate is a rock consisting primarily of cryptocrystalline silica, chiefly chalcedony, alternating with microgranular quartz. It is characterized by its fineness of grain and variety of color. Although agates may be found in various kinds of host rock, they are classically associated with volcanic rocks and can be common in certain metamorphic rocks. The stone was given its name by Theophrastus, a Greek philosopher and naturalist, who discovered the stone along the shore line of the river Achates () in Sicily, sometime between the 4th and 3rd centuries BC. Colorful agates and other chalcedonies were obtained over 3,000 years"