Brucite is the mineral form of magnesium hydroxide named in 1824 by François Sulpice Beudant for its discoverer, American minerologist and chemist Archibald Bruce. Colors vary and may include light blue, milky white, or lemon yellow. It crystals typically have a fibrous body what could be described as a chalky or pearly luster. The structure of the mineral is maintained only weakly, making the it fragile. It is also know for shearing into perfectly flat sheets due to its crystal cleavages laying parallel to their plates.
Brucite is common, but excellent examples are hard to come by. Notable finds include in Wood’s Chrome Mine in Lancaster County, Pennsylvania as well as in Baluchistan, Pakistan. Recently there was a major discovery of brucite yielding beautiful and rare yellow and lemon-yellow specimens, some of which are startlingly and gorgeously transparent. Because the mineral is so fragile it is usually mined by hand
Besides collecting it is used as a source of magnesium and in some flame retardantion applications.
Dioptase is an unusual mineral that is highly desired for its intense Emerald green color. It is a copper cyclosilicate mineral that varies from transparent to translucent. Very popular with mineral collectors he can be cut into small gems are also ground up and used as a pigment for painting. Dioptase typically forms as a secondary mineral and copper deposits created through the weathering and oxidation of the primary minerals in either limestone or calcite formations. It may be associated with other cupric minerals like malachite, chryscolla, and azurite. It is a trigonal mineral which forms six-sided crystals that termine in rhombohedra.
Dioptase is uncommon and usually found in desert regions . Within the United States, deposits are mostly restricted to the state of Arizona. Globally Kazakhstan and in particular the Tsumeb mine in Namibia produce some of the best examples of this mineral. Dioptase is also found in Congo and then Argentina in South America. Better examples of this mineral can be quite costly.
In modern times dioptase was discovered at the end of the 18th century in the Central Asian steppes in Kazakhstan. The Russian mineralogist’s who discovered it confused it four form of emerald. Despite having a similar color to emeralds dioptase actually has different optical and physical properties which differ enough the gemologists can easily distinguish one from the other. Dioptase has been discovered to have been used to decorate plaster statues dating back to before 7000 BC.
Dioptase dust is toxic due to its copper content an accidental ingestion can lead to serious problems. Jewelers and fasteners should wear protective masks and ideally use a glove box to avoid inhaling or ingesting particles during the cutting polishing and cleaning processes. Finish pieces however typically pose no hazard. Because of the cleavage pattern impossible fractures dioptase is should usually be cleaned with a mild detergent warm water and a soft brush. Dioptase in general tends to be very fragile and specimens should be handled with great care.
Learn more about the physical characteristics and crystallography of dioptase at mindat.
Dioptase ist ein ungewöhnliches Mineral, das wegen seiner intensiven smaragdgrünen Farbe sehr begehrt ist. Es ist ein Kupfercyclosilikatmineral, das von transparent bis durchscheinend variiert. Sehr beliebt bei Mineraliensammlern kann er in kleine Edelsteine geschnitten werden, die ebenfalls gemahlen und als Pigment zum Malen verwendet werden. Dioptase bildet sich typischerweise als sekundäres Mineral und Kupferablagerungen, die durch Verwitterung und Oxidation der primären Mineralien in Kalkstein- oder Calcitformationen entstehen. Es kann mit anderen Kupfermineralien wie Malachit, Chrysokoll und Azurit assoziiert sein. Es ist ein trigonales Mineral, das sechsseitige Kristalle bildet, die in Rhomboedern enden.
Dioptase ist ungewöhnlich und kommt normalerweise in Wüstenregionen vor. In den Vereinigten Staaten sind die Einlagen meist auf den Bundesstaat Arizona beschränkt. Weltweit produzieren Kasachstan und insbesondere die Tsumeb-Mine in Namibia einige der besten Beispiele für dieses Mineral. Dioptase kommt auch im Kongo und dann in Argentinien in Südamerika vor. Bessere Beispiele für dieses Mineral können sehr kostspielig sein.
In der Neuzeit wurde Dioptase Ende des 18. Jahrhunderts in den zentralasiatischen Steppen in Kasachstan entdeckt. Die russischen Mineralogisten, die es entdeckten, verwirrten es mit vier Formen von Smaragd. Obwohl Dioptase eine ähnliche Farbe wie Smaragde aufweist, weist sie tatsächlich unterschiedliche optische und physikalische Eigenschaften auf, die sich so stark unterscheiden, dass die Gemmologen sie leicht voneinander unterscheiden können. Es wurde entdeckt, dass Dioptase zur Dekoration von Gipsstatuen aus der Zeit vor 7000 v. Chr. Verwendet wurde.
Dioptasestaub ist aufgrund seines Kupfergehalts giftig. Eine versehentliche Einnahme kann zu ernsthaften Problemen führen. Juweliere und Befestiger sollten Schutzmasken tragen und idealerweise ein Handschuhfach verwenden, um das Einatmen oder Einnehmen von Partikeln während des Polier- und Reinigungsprozesses zu vermeiden. Endstücke stellen jedoch normalerweise keine Gefahr dar. Aufgrund des Spaltmusters sollten unmögliche Frakturen der Dioptase normalerweise mit einem milden Reinigungsmittel, warmem Wasser und einer weichen Bürste gereinigt werden. Dioptase neigt im Allgemeinen dazu, sehr zerbrechlich zu sein, und Proben sollten mit großer Sorgfalt behandelt werden.
Erfahren Sie mehr über die physikalischen Eigenschaften und die Kristallographie der Dioptase bei mindat.
Top Image Credit: Dioptase Locality: Tsumeb Mine (Tsumcorp Mine), Tsumeb, Otjikoto (Oshikoto) Region, Namibia A startlingly sculptural specimen! Pristine and perfect all around. Erik Louw was a miner on the dioptase stope who traded extensively and accumulated one of the finest Tsumeb miniatures collections, purchased in entirety by the Sussmans in the late 1990’s. 4 x 4 x 1 cm Dioptase-Lokalität: Tsumeb-Mine (Tsumcorp-Mine), Tsumeb, Region Otjikoto (Oshikoto), Namibia Ein erstaunlich skulpturales Exemplar! Rundum makellos und perfekt. Erik Louw war ein Bergmann auf der Dioptase-Station, der ausgiebig handelte und eine der besten Tsumeb-Miniaturensammlungen sammelte, die Ende der 90er Jahre vollständig von den Sussmans gekauft wurden. 4 x 4 x 1 cm 翠銅鉱産地：ナミビア、ツメブ鉱山（ツメブ鉱山）、オシコト地方、ツメブ驚くべき彫刻標本！ 手付かずで完璧です。 Erik Louwは、1990年代後半にサスマンによって完全に購入された、ツメブの最高のミニチュアコレクションの1つを幅広く取引し、蓄積した翠銅鉱の鉱夫でした。 4 x 4 x 1 cm By Rob Lavinsky, iRocks.com – CC-BY-SA-3.0, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10109320
The February birthstone is amethyst. A form of non-fluorescing hard stone quartz whose typically purple shading comes from irradiation of iron or transition element impurities, amethyst was once considered one of the cardinal, or most valuable, gemstones. Occasionally exhibiting secondary shades of blue or red, the beautiful stone is highly popular among mineral collectors, crystal healers, art lovers, lapidaries. While not considered as valuable as it once was due to recent discoveries of large deposits of the mineral, amethyst often produces stunning jewelry.
Traditionally most carved gemstones in the west are a form of quartz, the carving techniques adopted for quartz also apply to amethyst. Amethyst deposits have been found on almost every continent and it’s availability was a key factor in it’s popularity as a carving medium of artisans in antiquity. Deposits have been found in Brazil, Uruguay, Austria, Russia, Zambia, and Korea, as well the eastern and southern areas of the United States, including Texas, North Carolina, and the Lake Superior Region.
Amethysts was carved and treasured by cultures such as those of Japan, Iran, Greece, Rome, Egypt, the Anglo-Saxons and others. Different cultures each put their own spin on the importance, meaning and value of the stone. It was highly treasured by Russian Empress Catherine who sent thousands of miners into the Ural mountains seeking the gemstone. In ancient Rome, the purple color of the gem was associated with the purple color reserved for the elite and the emperor. The medieval Catholic church’s bishops prized amethyst’s color. The ancient Egyptians worked the material into amulets for protection against harm. Moses the prophet is said to have described amethyst as representing the spirit of god. The ancient Greeks believed the stone offered protection from drunkenness. The Tibetans created rosaries from the stone and considered it sacred to Buddha. Leonardo Da Vinci wrote that amethyst quickened intelligence and dissipated evil thoughts. The Anglo-Saxons fashioned beads, while was used for intaglio.
In this article we present a visual tour of the different ways amethyst has been used in art, both ancient, antique, and modern.
Amethyst intaglio portrait of Julius Caesar, Roman, 50-40 B.C.E.
A recent study in Frontiers in Earth Science reveals that researchers discovered quartz crystals in the stomach of a bird that lived alongside the dinosaurs. The bird, a member of the Enantiornithes clade of fossil birds, appeared to be a sensational discovery, as previously there had never been a find which preserved any traces of food in the fossils stomach which would clue researchers in to the diet of the animal. Many modern birds have what’s called a gizzard, a thick and muscular portion of the stomach used to help digest food. Often birds swallow small stones know as gizzard stones, which make their way to the gizzard itself where it helps to crush tough or difficult to digest food. These stones are know as gastroliths and have been found in some dino and bird fossils providing hints as to the diet of those animals. The presense of stones in the stomach, though isn’t defiinitive as to the purpose of the stones. There are some modern birtds of prey that swallow rocks to help move material through their digestive tract, cleaning it out, and it’s hard to differentiate between a gastrolith and a gastrolith that is a gizzard stone without knowing anything about the diet and habits of the animal using the stone. In the end, the reesearchers determined that the quart material found where the birds stomach would have been probably was a gastrolight at all. After exposing the supposed gastroliths to X-rays and a scanning electron microscope it was determined that the rocks were actually chalcedony crystals, quartz that grew in sedimentary rocks. There is evidence of chalcedony crystals forming with a clamshell, or replacing minerals in fossil bones. Furthermore, the crystals in this case were all connected in a thin sheet rather than separate rocks. The rocks were also much larger than would be expected of rocks swallowed by a bird that size. In the end there just wasn’t enough evidence, and some negative evidence against the idea that the rocks were in the birds stomach. Just goes to show, never count your gastroliths before they’s been swallowed.
We don’t have any examples of Enantiornithes, but you can check our our collection of fossils for sale here.
Top image is a photograph of the holotype of Zhouornis hani, a type of Enantiornithes, By Yuguang Zhang, Jingmai O’Connor, Liu Di, Meng Qingjin, Trond Sigurdsen, Luis M. Chiappe – https://peerj.com/articles/407/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=33060650
If the mineral is green and gorgeous there is a good chance it’s malachite. Like its copper cousins Turquoise, Azurite, and Chrysocolla, Malachite is found in copper deposits. It first became useful to humans as an ore used by the ancients to produce copper metal. Today, its primary use is decorative: bracelets, necklaces, pendants, as a gemstone and cabochon, and other types of jewelry. It’s also popular as a tumbled stone and as a standout display specimen for rock and mineral collections.
North American deposits include Mexican deposits in Milpillas; American deposits in Bisbee, Morenci, Bingham Canyon and others; African deposits in Namibia, Gabon, Zambia, Uganda, and The Democratic Republic of Congo (Zaire). Russia was at a one a major source of Malachite, particularly gem quality stones, however most of these deposits have been mined out and eclipsed by the quantity and quality of the African deposits. African mines product spectacular massive malachite specimens as well as gem quality malachite, and plancheite, cuprite and carrollite are also present in these deposits.
Malachite from a Smelter’s Crucible, Egyptian, Joint reign of Hatshepsut and Thutmose III, ca. 1479–1458 B.C., 18th Dynasty
Copper deposit don’t typically yield huge amounts of malachite. Previously, Russia was the only significant source of a large volume of gem-grade malachite, but as the Russian mines have declined and the African mines became available the African finds have far exceeded Russian production. African banded layers malachite is sometimes over a foot thick with very tightly packed submicroscopic needle crystals. Since the opening of the African mines, the mineral market has great cutting-grade malachite with bands of very light green to almost black- green.
Malachite was well known to the ancients. It’s Latin name, “Molchitis” derives from the Greek “molochites lithos” whose meaning is “mallow green stone” due to the mineral’s resemblance to the mallow plant’s leaves. Some evidence exists o Malachite mining in Britain at the Great Orme Mines perhaps as far back as the 3rd and 4th millenia B.C. There is also archaeological evidence of Malachite mining and smelting to produce copper 3,000 years ago in the Timna Valley, associated with King Solomon’s Mines in modern day Israel, where it is still mined to today to produce copper.
Lapidary, work with malachite requires a facemask. The copper carbonate dust from Malachite is poisonous. Most lapidaries use water to cut down on the dust in the air. Undercutting is often a problem during polishing, since each malachite band has a slightly different Mohs hardness, however experienced lapidaries shouldn’t have a problem. Banded malachite is always beautiful no matter how it is used.
Qing Chinese Malachite Carving, Late 18th – Early 19th Century. Seated Luohan With Servant
Above is an outstanding example of carved malachite. A Qing era Chinese art work originating in the late 19th through early 20th century, it depicts a seated luohan, or one who has achieved enlightenment. This particular luohan is identified as Nakula who sits in meditation with a rosary; a boy-servant attends at his feet. From his long eyebrows and position beneath a tree. Carved writing in the upper right corner is a poem of praise for Nakula in the upper right was authored by the Jiaqing emperor (r. 1796–1820) and inscribed in the hand of his elder brother Yongxing (1752–1823).
French Monumental Malachite Vase. Lapidary Work Early 19th Century, Pedestal And Mounts By Pierre Phillippe Thomire
The monumental vase above is crafted from Russian malachite, bronze, gilt bronze and a filling material. Malachite grows in layers of tiny crystals its colors correlating with different crystal sizes, creating the pattern. During the late eighteenth and nineteenth centuries, most malachite came from Russian mines by the noble Demidov family. The family exploited hardstone quarries and metal deposits located on their estates in the remote Ural Mountains. In the 1820s on of the great discoveries in the history of semiprecious stones happened when an enormous malachite boulder around five hundred tons was unearthed there. Malachite is extremely brittle, so only small display objects can be cut from single blocks of the material. Large objects require a core structure, to which the malachite can be attached in thin pieces, effectively a veneer. Russian craftsmen developed a method to use the stone’s natural pattern and a precision cutting technique to form a continuing or “endless” ornamentation. This type of veneering appears nearly seemless and is called “Russian mosaic”.
The Demidov family used the flashy appearance of malachite to improve their social status, filling their palaces with the material and even decorating an entire room with the green stone, which inspired Czar Nicolas I to commission the famous Malachite Room in the Czar’s Winter Palace in Saint Petersburg.
The monumental vase above is modeled on an ancient Roman bell-shaped krater, the most famous example of which is the first-century Medici Vase, now in the Galleria degli Uffizi, Florence. This shape was quite much admired through the early nineteenth century. Count Nikolai Demidov commissioned this particular malachite vase for his villa at San Donato, near Florence. Unlike with the Russian mosaic technique, large areas of this vase’s surface is composed of small malachite particles mixed with filling substance in the same way as modern terrazzo. This raw malachite was probably transported from one of his mines to Florence to be shaped and finished by local artists not trained in the specialized Russian technique. The vase would then have been sent onwards to Paris to be fitted with its mounts and pedestal.
The gilded bronze winged female figures on the body of the vase represent Fame. Their trumpets are shaped like handles, although the vase is too heavy to be lifted like a loving cup. A gilded bronze laurel garland of laurel (Laurus nobilis) runs under the lip mount. The laurel had been adopted by Lorenzo de’ Medici (who was also a lavish patron of the arts) as an emblem of his house with the motto “Ita ut virtus,” or “Thus is virtue”— that is to say, virtue is evergreen. It’s use here implies that the Demidov’s hoped that their fortune would also be evergreen.
The mounts and bronze pedestal were made by Pierre-Philippe Thomire (1751–1843), known throughout Europe for his bronze decorations and ornamental sculpture. He established a reputation before the French Revolution with beautiful mounts for Sèvres porcelain vases. In 1804 he founded a workshop that produced furniture as well as luxury bronzes.
Malachite with Azurite
Description of Malachite
3.5 to 4.0
3.6 to 4.0
Perfect in one direction, fair in a second direction
Most examples are opaque while crystals are translucent
Polishes to a very bright luster. Large specimens tend to be dull and earthy. Silky luster in fibrous examples. Unusual crystals trend from vitreous to adamantine.
Even though chyrsocolla and azurite are both copper based minerals, malachite is a better indicator of the presence of significant copper deposits. The Copper Queen mine in Brisbee was created on the basis of malachite deposits.
Malachite Copper Crescent from Zaire (Democratic Republic of Congo)
Image of Malachite Taken Under a Stereoscopic Microscope
Malachite has a number of different cultural meanings and associations. For the Chinese, Malachite is a lucky stone for those born in the Year of the Rabbit or Year of the Tiger. For the ancient Egyptians, the color green was associated with death and the power of resurrection – as well as new life and fertility. They believed that the afterlife contained the “Field of Malachite”, an eternal paradise resembling their lives but with no pain or suffering. They also used the material in powder form for cosmetics, particularly to try to resemble Horus, the falcon headed god Those who believe in crystal healing, crystal spirituality believe the stone has any number of healing, or metaphysical properties on the body, spirit or chakra.
View our collection of beautiful malachite specimens for sale, perfect as display piece on your table or mantle, for your collection, or for use in spiritual or crystal healing.
A gorgeous blue mineral occurring in silica poor igneous rocks which contain other silica poor minerals and no quartz. , Sodalite’s distinctive color ranges from royal blue to light blue and white. It is often confused with lazurite, lazulite and azurite. Less common forms varieties include Hackmanite (found in Afghanistan) which is a tenebrescent violet-pink. Other forms include transparent Sodalite, which is very rare, and grayer and paler samples which sometimes fluorescent. Sodalite-bearing rocks include: nepheline syenite, trachyte, and phonolite and deposits are found in Namibia, Greenland, Russia, Brazil, Italy, and Canada (Ontario and British Columbia). Small colorless crystals are found at Monte Somma, Vesuvius and at Vico Lake, near Viterbo in Italy. Sodalite deposits in the United States are found in Arkansas and Maine.
A Remarkable, Sharp, Isolated Hackmanite (Sodalite) Crystal from Koksha Valley, Badakhshan Province, Afghanistan
Origin of the Name Sodalite
The name Sodalite is derived from the sodium content of the mineral and was by a Glasgow chemist, Professor Thomas Thomson. The mineral was first described after being discovered in the Ilimaussaq Alkaline Complex, Narsaq, Greenland. Technically the name refers to a group of minerals with a similar isometric structure and related chemistry, and named after the most common of these minerals, also named sodalite. The Sodalite group is a member of the feldspathoid minerals. Other members of this mineral group include: Nosean, Hayne, and Lazurite.
Azul Bahia Granite – Sodalite Metasyenite from the Precambrian of Brazil.
Other Neat Facts!
Primarily used for decorative purposes particularly as cabochons for jewelry, beads and tumbled stones. Sodalite is one of the few blue rocks used for that purpose that is still reasonably priced.
Crystal sodalite tends to be rare, but large granular masses have been found near Bancroft, Ontario. Nearly 130 tons was of the material was mined from the Bancroft deposit and shipped to the U.K to decorate Marlborough House mansion in London – the headquarters of the Commonwealth of Nations and at one time the residence of the Princess of Wales.
Close Up View of Sodalite
View our collection of beautiful sodalite specimens, perfect as display piece on your table or mantle, for your collection, or for use in spiritual or crystal healing.
Other names for sodalite include alomite, bluestone and canadian lapis.
Second image by Rob Lavinsky, iRocks.com – CC-BY-SA-3.0, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10451113.
Third image by James St. John – Azul Bahia Granite (sodalite metasyenite, Itabuna Syenite Complex, Neoproterozoic, ~676 Ma; Fazenda Hiassu, Bahia State, Brazil) 12, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=58087558
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