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Many more pseudomorphs are nucleated from the azurite matrix interface than nucleated from the azurite crystal surface. In conclusion, the analysis of these pseudomorph illustrations suggests the following: Azurite can continue to grow on azurite while malachite pseudomorphs are growing within. The four azurite crack surfaces have conchoidal fractures on one surface, complete coverage of new secondary azurite on a second surface, and two vertical surfaces with mixed conchoidal areas and new azurite. The governing reaction for malachite growth is: Two azurites plus one water yields three malachites plus carbon dioxide. [Extracted from the article]

Most of the micromineral inclusions generated by the RMR process in Schickler apatite appear to be REE minerals; an example EDS spectrum of a typical REE inclusion is shown in figure 2. The I T i I O i I T i modules within these minerals can be used to derive many mineral properties by first principles, e.g., habit, cleavage angles, and symmetry/polytypism (fig. 1). Among other minerals, striking red-brown apatite crystals, to 10+ cm, can be found hosted within the dissociated calcite-fluorite carbonatite matrix. However, the diversity of these modular rock-forming minerals results in complexity in terms of the crystal structures and crystal chemistries of this mineral family. [Extracted from the article]

One spodumene crystal exceeded 11 meters in length, and crystals in excess of 2 meters in length are common. It is spodumene-rich with more than 50 percent spodumene in some of the upper portions of the pegmatite. These spodumene and montebrasite crystals are comparable in size to the famous crystals from the Etta and Hugo pegmatites in South Dakota, where 14-meter spodumene crystals and 7-meter amblygonite (likely montebrasite) occur (Rickwood [1]). [Extracted from the article]

Brittany MacRostie is a Denver-area artist who not only creates paintings of mineral art, but also experiments and uses many different media. Although MacRostie generally uses watercolor for her mineral paintings, she enjoys bringing minerals into some of the other artforms she has experimented with, including ink, digital illustration, woodburning, and needle felting. [Extracted from the article]

Ksenia Levterova (b. 1986), Ukraine; her art was published in the July/August 2020 issue of Rocks & Minerals, pages 372-374. Fred Wilda (b. 1941), United States; his art was published in the March/April 2002 issue of Rocks & Minerals, pages 124-125. Tama Higuchi (b. 1999), United States; her art was published in the May/June 2021 issue of Rocks & Minerals, pages 248-250. [Extracted from the article]

Iconic Specimens Doubtless, these large almandine garnets will become known as classics, similar to the almandine crystals from Russell, Massachusetts. Large, sharply formed almandine crystals from Mt. Marie were first recovered in May 2017. The pegmatite units, exposed between overburden-concealed areas, are sufficiently discontinuous to prevent determining whether the mountain crest is one pegmatite or a swarm of several pegmatites. These garnets are late crystallization products, which formed near the end stage of the primary pegmatite crystallization, as indicated by the crystals' location in contact with quartz core segments, which usually (but not always) is the last crystallized part of the pegmatite (London [13]; Roering [16]). [Extracted from the article]

Tourmaline mining in Maine began with the first find of gem-quality tourmaline at Mt. Mica in 1820 and continues today at numerous localities. In October 1972, on the eastern slopes of Plumbago Mountain in Newry, Maine, the largest single discovery of gem-quality tourmaline in North America was unearthed - more than a ton in all. Mt. Mica, the Havey quarry, and the quarries at Mt. Marie are all notable contemporary locations for gem tourmaline in Maine. [Extracted from the article]

In the late 1960s, 1970s, and 1980s he focused extensively (though by no means exclusively) on Tsumeb (fig. 2), during which time he and his business partner, Frederick "Rick" Ludlow Smith, were responsible for bringing vast quantities of Tsumeb specimens to collectors in the United States and beyond. At the Tucson Gem and Mineral Society (TGMS) Show in 2014, and again in 2015, I had the enormous privilege of sitting down with Charlie to discuss some of his memories of visits to Tsumeb and his role in bringing so many Tsumeb specimens from southern Africa to the United States. B M. S.: I read somewhere that you have estimated that the value of dioptase from Tsumeb exceeded the value of all other Tsumeb collector minerals combined? Charlie was much more than a successful mineral dealer; his knowledge of specimen mineralogy was quite extraordinary, and he had a willingness to share that knowledge in a friendly, modest, and relaxed manner. [Extracted from the article]

Even though beryl mining in New Hampshire has rarely been economically viable, the mineral clubs of New Hampshire proposed beryl as the state mineral because it is essential for a modern economy and because there are notable occurrences in the state. Bertrandite in LCT pegmatites is an alteration product of beryl, and in some cases, it completely replaces beryl or lines the cavities left by dissolved beryl crystals. Beryl is a beryllium aluminum silicate, Be SB 3 sb Al SB 2 sb Si SB 6 sb O SB 18 sb , containing approximately 5.3 weight percent beryllium in ideal beryl with slightly less in common beryl, a sufficient concentration for beryl to be considered an ore of the metal. Beryl: Be3Al2Si6O18 Beryl is the most widespread beryllium mineral and was the most important ore of beryllium until superseded by bertrandite in the early 1960s. Bob Janules, a New Hampshire mineral field collector, reviewed the first draft, and his experience in collecting New Hampshire beryllium minerals greatly contributed to this article. [Extracted from the article]

Penetration Twins Penetration twins of the sort seen in neptunite are composed of two individuals that are identical (ideally) and cross at an angle that is determined by the twin law and described by the Miller indices of the twin law. Comparison with figure 11 shows that the correct twin plane is (10 Graph HT ht ), not (90 Graph HT ht ). One of these planes is the true twin plane - it has the same Miller indices as the twin law; the other one, at right angles, has different and in most cases irrational indices and is referred to as a contact plane but not a twin plane. The crystallographic "law" of simple rational indices states that major planes on crystals, including both faces and twin planes, typically have Miller indices involving small integer values (usually 5 or less). [Extracted from the article]

Cathodoluminescence (CL) measurements from a few single crystals and fragments of Pulsifer apatite in general showed areas of bright yellow-green CL emission corresponding to pale purple or white parts of the apatite. Purple apatite is a rare variety of fluorapatite that is widely distributed in many rock types. Description of the Roebling Apatite The Roebling apatite is considered by many mineral collectors to be one of the finest specimens of fluorapatite ever discovered. The best purple apatite specimens were mined from the Pulsifer quarry and include the world-famous Roebling apatite, which currently resides in the mineral collection of the National Museum of Natural History, Smithsonian Institution (fig. 1). [Extracted from the article]

It certainly has the longest history of exploitation of all other minerals in the region and perhaps is even the oldest mineral/gemstone exploited by man since the Neolithic Period (Wyatt, Bariand, and Filippi [26]). Identified in the gemstones were inclusions of calcite and pyrite, two minerals known to occur in lazurite but not common in afghanite. Afghanite, (Na,K) SB 22 sb Ca SB 10 sb (Si SB 24 sb Al SB 24 sb O SB 96 sb )(SO SB 4 sb ) SB 6 sb Cl SB 6 sb (fig. 1), is a member of the cancrinite group of feldspathoid minerals with a crystal structure defined as an eight-layer member of this group (Ballirano et al. [5], [2]; Ballirano, Maras, and Buseck [4]). Geology, Gems, and Minerals of Afghanistan The regional geology of Afghanistan has been succinctly summarized by the British Geological Survey (BGS) (https://www..bgs.ac.uk/AfghanMinerals/geology.htm; accessed May 2021). [Extracted from the article]

An examination of specimens suggests the sand-calcite crystals formed in a deposit of fine-grained loose quartz sand into which a mixture of rounded pebbles, from crystalline rocks unrelated to the original sand deposit, was added. Changed conditions cause crystallization to stop or it would cement the loose sand and sand crystals into a mass of sandstone; evidence of this is noted at several sand-calcite localities. Reproduced with permission Single sand-calcite crystals are found near the bottom of the sand layer, and with increasing height the number of crystals increases from doublets and triplets until they became crowded clusters (Barbour [1]). When minerals such as calcite (CaCO SB 3 sb ), gypsum (CaSO SB 4 sb -2H SB 2 sb O), and baryte (BaSO SB 4 sb ) form in sand beds, grains of sand are generally incorporated into the crystals. [Extracted from the article]

Although the quote is specific to the orebody of the now-abandoned marble quarry, it also suggests the potential for contact metamorphism and metasomatism that impacted and altered the actinolite and the specular hematite into nephrite and magnetite. Mineralogy/Petrology of the Nephrite Nephrite jade is essentially a monomineralic rock composed of amphiboles from the actinolite-tremolite series with occasional other impurities (Ling et al. [8]). B For well over half a century b , Southern California collectors have known about and tried to collect black nephrite jade with sparkling rosettes of magnetite from a unique deposit adjacent to the Verde Antique Marble quarry (Sec. 28, T. 7 N., R. 2 W., San Bernardino base and meridian). Magnetite in nephrite has been identified in many other nephrite jade deposits worldwide. [Extracted from the article]

Mike was active around the world - I would see him in Munich or Sainte-Marie-aux-Mines, but it is certainly Mexico that brought Mike to the attention of the collector world. Along with Sandra, Mike collected at Jerome, Arizona, where he made a find that plunged him deep into the mineral business - the azurite rosettes recovered were snapped up by collectors, and a mineral dealer was hatched. Mike's son, Jason, had been working for his father for many years as comanager, which would free up Mike to go collect the next new find. [Extracted from the article]