Jewellery Insides’ Post

The Purcell Sill* is a famous marker horizon within Glacier National Park (GNP) and throughout much of the Belt Supergroup. This stark, black diorite** stripe in the sedimentary strata also provides a textbook example of contact metamorphism. The Precambrian age (1,600 to 800 Mya) Belt Supergroup sedimentary rocks (top photo) of GNP were deposited in a shallow sea, and show little to no metamorphism despite their age. Underneath the Belt series are Cretaceous shales that are only ~100 Mya. Beginning about 75 Mya, the collision of tectonic plates during the Laramide Orogeny resulted in an enormous wedge of Belt rocks (over 24 km thick) being driven ~80 km eastward (comment cross section). Called the Lewis Overthrust, this slab of rock easily rode over the weak shale like slipping on a banana peel, although geologists prefer the more refined term ‘décollement’ (French décoller, 'to detach from'). Throughout most of the park, the Purcell Sill stands out as a ~100 to 300 ft. (~30 to 90 m) thick fine-grained intrusive within the Siyeh Limestone (1,100 Mya). It is now sandwiched between strips of white, low-grade marble that formed as heat from the cooling magma baked the limestone (contact metamorphism, lower photo). This heat also drove out organic material, bleaching the rock and causing more contrast between the dark sill and the marble. * There is a Purcell Lava found in GNP, and the sill and lava are not the same age, so the sill is now referred to as the ‘magmatic sill’ to avoid confusion. However, everyone still calls it the Purcell Sill. ** While all the GNP publications use the term diorite for the #sill, it is primarily an alkaline olivine #diabase. The grain size and petrography appear to be variable (comment) within the intrusive, however, they are unimportant for the purposes of this post. #Geology #nature #Montana

The world of gemstones is a mesmerizing kaleidoscope of colors and textures, with each stone telling a unique story of geological marvels. While most people are familiar with popular gems like diamonds, rubies, and sapphires, there exists a captivating realm of unusual and rare gemstones that often escape mainstream attention. In this exploration, we unveil the hidden treasures that might just become your next favorite gemstone. 1. Taaffeite:  - Often mistaken for spinel, Taaffeite is a rare and stunning violet-pink gemstone... Enjoy the read https://lnkd.in/d4HacHzW

It may come as a surprise, but the largest faceted diamond in the world, according to the Guinness Book of World Records (2006), is the Enigma, a 555.55 carat very dark to black stone cut form a ca. 800-carat rough reportedly found in the 1990s and cut into a 55-facet free form presented at Sotheby's in 2017. This stone is about 10 ct heavier than the largest gem diamond on record, the Golden Jubilee (545.65 ct) and 25 ct heavier than the historical Cullinan I diamond or The Great Star of Africa (530.20 ct). The interesting aspect about this stone is the fact that it is a carbonado (from the Portuguese “carvão”, charcoal), that is a very dark (usually black), opaque, low density material with a characteristic surface patina that occurs in massive equidimensional opaque agglomerates of micro-sized randomly oriented crystals, thus being a polycrystalline aggregate, mostly used historically for industrial purposes (e.g. drilling tool) due to its high tenacity and hadrness. It occasionally occurs in specimens weighing over 1,000 carats, like the 3,167 ct Carbonado do Sérgio found in Brazil at Chapada Diamantina in 1905. Known reported occurrences include only Brazil, first described in 1841, and Central African Republic. The origin of carbonados is still debatable between extra-terrestrial sources (the most strong hypothesis) to still unknown geological mechanisms. The question here is: as a polycrystalline aggregate, can it be called a diamond and colour graded as such? Among other things, I'll be asking this very question at the forthcoming Scottish Gemmological Association Conference near Cumberland this weekend (more info at https://lnkd.in/dT7ZHCZx). Photos © Sotheby's #diamond #gemstones #geology #luxury #record

"Pectolite" is primarily found in metamorphic and igneous environments. It commonly occurs in hydrothermal veins associated with volcanic activity, as well as in contact metamorphic zones where hot magma comes into contact with pre-existing rocks. It can also be found in sedimentary deposits formed from the weathering and erosion of pectolite-bearing rocks. Pectolite has been discovered in various locations around the world. One of the most famous and significant occurrences of pectolite is in the Dominican Republic, where a blue variety of pectolite called Larimar is found. Larimar is highly valued for its unique blue coloration and is used in jewelry and decorative items. Other notable sources of pectolite include Canada, the United States, Italy, Germany, Russia, and South Africa.

Did you know the cat's eye #tourmaline? 1. What is the cat's eye? The effect is caused by microscopic, parallel inclusions of #rutile, which create a narrow band of light that appears to move across the surface of the gemstone. 2. Colors: 🌈 Various colors, including green, yellow, brown, and black. 🌈 Particularly found in green and pink varieties. 3. Cut: Often cut into a #cabochon shape to enhance the #chatoyancy effect. "The more I know, the more I realize I know nothing." #socrates #gems #gemology #gemme #gemmologie #gemstrends #catseyes #tourmalines To know more👇🏻

15 Facts About Peridot We Bet You Didn't Know Peridot is a delightful green gemstone that is, in many cases, used in jewelry. Yet, do you have at least some idea that peridot is additionally accessible in crystal form? Peridot crystals are similarly as stunning as their gemstone partners and have various exceptional properties that settle on them, a famous decision for gem devotees. Peridot crystals are an assortment of the mineral olivine. They structure somewhere down in the world's mantle and are brought to the surface by volcanic movement. Peridot crystals are commonly found in volcanic rock, where they have been gradually cooling and solidifying for more than millennia. Perhaps the most striking thing about peridot crystals is their lively green tone. This green tint is brought about by the presence of iron in the gem's construction. Visit Us : https://lnkd.in/daUjmFBB

#online #gemstones #handmadejewelry #jewelrydesigner #florencejewelshop A lava stone bead is one of my favorite beads to make a piece of jewelry. I visited Sicily a few years back and wanted to visit the Etna. That is one of the largest volcanos in Western Europe. It wanted to see that powerful volcano. Last August we visited Iceland, the land of the vulcanos. Something attracts me to that kind of natural power station. Also here is the cold and blackness of the stones and the contrast of the glaciers, and the white snow. The blue glacier lakes with the icebergs and the crystal clear water. Knowing that one of the vulcanos can explode any minute, without warning. And not only add a fresh layer of lava to the soil that already is loaded with lava in many different shapes. But such an outbreak makes the air and the whole area black, from the dust that comes out of the volcano. Maybe you don’t like outbursts of vulcanos, maybe you think they are dangerous and can take lives. And you are right. But vulcanos also make the soil fertile and give mankind a beautiful (gem) stone: the lava stone. And that lava stone, which I use often to make the most beautiful pieces of jewelry, is the subject of this blog post. https://lnkd.in/eux4bjzv

𝗘𝘅𝗽𝗹𝗼𝗿𝗶𝗻𝗴 𝗠𝗮𝗿𝗸𝗲𝘁 𝗧𝗿𝗲𝗻𝗱𝘀 𝗮𝗻𝗱 𝗜𝗻𝗻𝗼𝘃𝗮𝘁𝗶𝗼𝗻𝘀 𝗶𝗻 𝗔𝗴𝗮𝘁𝗲 𝗝𝗲𝘄𝗲𝗹𝗿𝘆 𝗮𝗻𝗱 𝗗𝗲𝗰𝗼𝗿 The global Agate market was valued at 342.89 Million USD in 2022 and will grow with a CAGR of .96% from 2022 to 2028, based on Stats and Research newly published report. 𝐆𝐞𝐭 𝐌𝐨𝐫𝐞 𝐈𝐧𝐬𝐢𝐠𝐡𝐭𝐬 𝐚𝐧𝐝 𝐆𝐫𝐚𝐛 𝐃𝐞𝐭𝐚𝐢𝐥𝐞𝐝 𝐏𝐃𝐅: https://lnkd.in/dTtxyJ9U Agate is a type of microcrystalline quartz mineral, characterized by its fine-grained texture and banded appearance. It is formed in the cavities of volcanic rocks or ancient lava flows through the deposition of silica-rich fluids over millions of years. Agate typically exhibits concentric banding, layering, or other patterns in a variety of colors, ranging from translucent to opaque. It is a popular semi-precious gemstone used in jewelry, ornamental objects, and lapidary work. 𝗕𝘆 𝗔𝗽𝗽𝗹𝗶𝗰𝗮𝘁𝗶𝗼𝗻𝘀: Grind Products Decoration #agate #gemstone #mineralspecimen #crystalhealing #naturalbeauty #geology #rockhounding #crystallove #lapidary #mineralogy #snr

June Birthstone Alexandrite Gemstone Overview A relatively modern gemstone, alexandrite was discovered in Russian emerald mines located in the Ural Mountains. Legends claim that it was discovered in 1834 on the same day that future Russian Czar Alexander II came of age; it was named to honour him. Often described as “emerald by day, ruby by night,” alexandrite is a rare variety of the mineral chrysoberyl that changes colour from bluish green in daylight to purplish red under incandescent light. This chameleon-like colour shift is the result of its uncommon chemical composition which includes traces of chromium, the same colouring agent found in emeralds. The unlikelihood of these elements combining under the right conditions makes alexandrite one of the rarest and most expensive gemstones on Earth. The alexandrite mined from Russia’s famed deposits set the quality standard for this gemstone. Today, most alexandrite comes from Sri Lanka, Brazil, and East Africa, generally paling in comparison to the vivid colours of Russian gemstones. With a hardness of 8.5 on the Mohs scale, alexandrite is softer than sapphire and harder than garnet—the other gemstones that can change colour. However, due to its scarcity, alexandrite is more valuable than most gemstones, including rubies and diamonds.

Discover the beauty of Rose Quartz, a variety of Quartz known for its delicate pink hue. This gemstone forms in pegmatites at temperatures below 400°C, often in massive form. Its colour comes from trace amounts of titanium, iron, or manganese. Scroll for the Video! #WorldwideShipping - info@bmcc.co.za | +27 54 050 4977 https://lnkd.in/dNEGdu64 #BushmanlandMinerals #NorthernCapeMinerals #ForTheLoveOfStone #RoseQuartz #LuxuryLiving #GeologyRocks #RoseQuartz"