Indholdsfortegnelse for November - December 2025 i Rock and Gem

It may seem cliché, but I can’t believe it’s the holiday season already. I hope as you get this issue, you’re having fun and enjoying the festivities. We’ve got a lot packed into this issue. I enjoyed reading all the stories, but a few stood out. One was Jim Brace-Thompson’s piece on crafting with precious metal clay. I love crafts and have put this on my list to try. Another was Bruce McKay’s article on obsidian in tequila country. The workings of our Earth are always awe-inspiring and thinking about how this obsidian was formed is incredible. Also, high on my list was Mark Farrell’s article on diamond buying. I’ve seen so many stories about the rise in man-made diamonds and diamond alternatives. I’m not in the market for one…

Intaglio artworks have evolved from their ancient origin and styles as utilitarian seals to contemporary fantasies as deep reverse intaglios. Several gem artists worldwide are recognized for their very individual style of intaglios. INTAGLIOS & GEM ENGRAVING Intaglios are gemstone carvings with the design sunk below the surface of the stone. The engraving is incised, often in reverse when it needs to form a seal capable of taking impressions. The depth of an intaglio can vary, from very shallow for heraldry, seals and inscriptions, to very deep, for decorative designs. The word intaglio (the ‘g’ is silent, pl. intaglios) comes from the Italian “intagliare,” meaning “to cut in, to engrave.” It is also called “esoglyph,” from the Greek “eso” meaning “in + glyph.” Gem engraving is one of the most…

It’s easy to think that everything has already been found and there is nothing new to discover. On the contrary, discoveries in paleontology are being made every year. New plant and animal species and even new dinosaurs are being discovered in the field. Some are even being rediscovered in Museum collection rooms. But this is the story of a new invertebrate, an echinoderm fossil found at the Penn Dixie quarry in Hamburg, New York. ABOUT PENN DIXIE The Pennsylvania Dixie Cement Company originally owned and operated the Penn Dixie quarry site and closed its Hamburg quarry in the 1970s. The property was sold to a private businessperson. Then, in 1995, it was purchased by the Town of Hamburg and deeded to the nonprofit Hamburg Natural History Society. Since then, there…

Turquoise is a favorite with everyone from collectors to casual jewelry wearers, with its vivid sky-blue to greenish hues. This mineral’s color is a fashion must-have since it is considered a universal color that looks good on everyone, from those with warm and those with cool undertones in their skin. Known as one of the world’s oldest gemstones, turquoise has been mined and treasured across the globe and cultures from Ancient Egypt to the American Southwest. Holding steady value through the years, turquoise is used in fine jewelry, inlay work, and as a symbol of protection and good fortune. Formation and Geolo Turquoise is a hydrous phosphate of copper and aluminum with the chemical formula CuAl6(PO4)4(OH)8·4H2O. Its color comes from copper, which produces shades ranging from robin’s egg blue to…

There is a beauty and mystique surrounding gemstones found in cold and remote areas of the world. An increased desire for these coveted stones is born from a combination of rarity, difficulty in mining (and thus elusive nature) and in some cases, hailing from countries with strict environmental and ethical practices. CANADIAN DIAMONDS Diamonds can be found in more than 30 countries, with major producers being Russia and various African nations. But Canadian diamonds are growing in appeal due to having a “paper trail” from mine to consumer. “The frozen terrains of the Northwest Territories and Nunavut have become hotspots for high-quality, conflict-free diamonds. Formed deep within the Earth’s mantle and revealed through volcanic pipes, these diamonds are ethically mined and often laser-inscribed with a maple leaf, proudly showcasing their…

Is Mount Rainer about to Erupt? A case study in media hype Back in July, it was all over the popular press: Danger! Mount Rainer is about to erupt! The deadly volcano is experiencing the largest earthquake swarm EVER! One after another, over 1,000 earthquakes were indeed striking Mount Rainer National Park in Washington State over an unusually extended period of several weeks. (Most swarms there last just several days.) This led newspaper and radio reporters, bloggers, and others to remind everyone: Mount Rainer is one of the most active of all the Pacific Northwest stratovolcanoes, with a dandy view of Seattle. An eruption would have devastating consequences for millions of people. Even with earthquakes too small to be felt and no damage reported, and even though the U.S. Geological…

During the 1860s, the American public had little interest in the then-obscure field of dinosaur paleontology. Knowledge of “dinosaurians” was sketchy at best and derived only from a handful of incomplete fossilized skeletons that had been mostly excavated in Europe. But dinosaur paleontology soon embarked on a sweeping transition. As a sudden rush of spectacular dinosaur-fossil discoveries began making headlines, museums across the country clamored to acquire the complete dinosaur skeletal mounts that drew crowds of visitors. By 1900, dinosaur paleontology had been reborn as a vibrant science with a huge public following. This remarkable transformation was largely due to the work of American paleontologists Othniel Charles Marsh and Edward Drinker Cope. In the late 1800s, Marsh and Cope, the preeminent paleontologists of their time, waged a 30-year-long, no-holds-barred, fossil-finding…

As visitors approach the Dutch island of Bonaire by sea or by air, they are greeted by rows of white pyramids of salt—the island’s main export for hundreds of years, white gold. The history of commercial salt production on this Caribbean island began with the Spanish occupation in 1499, followed eventually by the Dutch, who brought African slaves to the island to work the salt ponds, to today’s mega production of salt by Cargill Corporation. Why is salt so important? What are its uses? How does seawater transform into the usable products found in every home and water treatment plant in the world? And what part does the island of Bonaire play in this process? Here is a look at how this beautiful island paradise formed approximately 60 miles off…

Some of the most colorful and beautiful obsidians in the world are found in Jalisco State, Mexico, created by a massive volcanic eruption 95,000 years ago that produced extensive deposits of obsidian in a wide variety of colors and qualities. The volcano also created soils that are ideal for growing Blue Agave, the source of the most famous product of this region, Tequila. The Tequila is a bonus, but the amazing obsidian catches the heart of lapidarists. The gem quality obsidians mined in this area west of Guadalajara include rainbow, silver sheen, snowflake, spiderweb, pure black and gold sheen. These varieties can be found isolated from other types or found in the near vicinity of each other. Each variety occurs in a range of qualities for lapidary use, with the…

’Tis the season, sings Burl Ives, for silver and gold decorations on every Christmas tree. You need not be a professional silversmith with fancy equipment and years of training to craft a fine silver sand dollar to hang on that tree or to dangle from a pendant as a holiday gift. You can make one quickly and easily at your kitchen table if, like me, you opt for the lazy man’s approach to silversmithing using precious metal clay. PRECIOUS METAL WHAT? I first encountered precious metal clay, aka PMC, from a local crafts store owner who was demonstrating how to use it at our county fair. It looked easy, with minimal equipment or know-how needed, so—being a lazy man—it intrigued me. But (being a lazy man) I didn’t pursue it…

This holiday season, why not raise your best Austrian crystal to toast one of that country’s most significant mammoth fossil finds of the century? This discovery was thanks to winemaker Andreas Pernerstorfer, who was unexpectedly reminded of that homeowner’s tenet: There is no such thing as a simple renovation. It started in March 2024, when Pernerstorfer was intent on leveling an annoying slope to the floor of his family’s multi-generational wine cellar in Gobelsburg, roughly 50 miles (80 kilometers) northwest of Vienna. In doing so, Pernerstorfer uncovered what the Austrian Archaeological Association coined a “sensation” of much older vintage: Woolly mammoth bones, initially mistaken for decayed wooden floorboards, and dating back some 30,000 to 40,000 Neolithic years. Now, instead of pouring Riesling, researchers are pouring over bones of riesig (German…

I’ve admired Michelle Mai’s style since I started cutting and am excited to share one of their designs! Michelle Mai’s faceting designs are botanical-inspired, and as we approach an East Coast winter, it’s nice to remember that spring is around the corner and flowers will bloom again soon. The design is primarily a meetpoint with one non-meetpoint tier that you need to cut by eye. CUTTING THE DESIGN The pavilion is straightforward and should not pose any problems. One point to note is that P2 and P3 are only one degree apart. When cutting this, I decided to cut P1, G1, and P2 first and then cut in P3 with my 3k. This helped me avoid overcutting, but be careful, they come in quick! I approached the crown in two…

Harris Mountain is on the eastern side of the Chiricahua Mountains in Cochise County, Arizona. Just north of Harris Mountain is the Harris Mountain Mine Group, which is a group of former copper and lead mines. The mines are on land administered by the U.S. Bureau of Land Management. Malachite, azurite, and galena can be found in the dumps and outcrops at the portals to underground workings. COCHISE COUNTY HISTORY With a rich mining history and an especially violent past, Cochise County was carved out of the eastern part of Pima County in 1881 and named for the Chiricahua Apache War Chief Cochise, who died in 1874. ''Harris Mountain is on the eastern side of the Chiricahua Mountains. Much of the Chiricahuas are within Coronado National Forest or BLM land…

During the 19th century, the American public was largely unfamiliar with turquoise and slow to recognize it as a gemstone. But in 1898, a remarkable archaeological discovery in the arid, high-desert country of northwestern New Mexico suddenly made turquoise the focus of national attention. THE TURQUOISE TREASURE While excavating 1,000-year-old stone ruins in remote Chaco Canyon, archaeologists recovered more than 50,000 turquoise artifacts, mostly beads, pendants and inlay. Their finds included “. . . a small burial room with 24,932 turquoise beads and more than 700 turquoise pendants. One skeleton had a total of 5,891 beads and several pendants of turquoise . . ., another had 8,385 beads and more than 500 pendants.” As newspapers headlined the story of Chaco Canyon’s “turquoise treasure,” demand for turquoise began to soar and…