The YAG, an Yttrium-Aluminum Garnet is a man-made material with a garnet structure that does not have its counterpart in nature. It is mainly used in lasers and sometimes in jewelry as diamond...

The slice of opalized wood (Figure 1) is reportedly from Megyaszó, Szerencs District, Borsod-Abaúj-Zemplén County, Hungary, likely from Tetlinke Ditch[1]. It shows three distinct parts, a beige to...

The fossilized corals have been quite common in the gemstone market for years. Most of the time, the material is opaque and almost all the structure / anatomy of the calcium carbonate skeletons of the...

The colorfull gemstone cabochon (Figure 1) shows a particular graphical pattern that looks like pistachio slivers in a cake. Such appearance probably gives the 'fruit jasper' name to this gemstone...

In june 2024, visiting the Sainte Marie aux Mines Mineral Show, I came accross several pieces of aesthetic minerals showing tiny, long or short colorless needles standing on an orange ball, like an...

Apache Gold is the trade name given to an elegant black and shiny metallic gold rock found in the United Verde Mine in Jerome, Arizona, USA. The black host rock is reported to be a chlorite schist...

Initially published as a Gem note in the Journal Of Gemmology of the Gem-A. 2020, 37(4), 344–346. http://doi.org/10.15506/JoG.2020.37.4.344 Celestine (or celestite, coelestite) is named after the...

The material described in this report has been widely available in online stores. It has been sold for a while as white marble with red cinnabar inclusions from Mexico. The piece showed in figure 1...

The ornamental egg and sphere shown in figure 1 were bought from China as 'Glowing in the dark egg and sphere'. Without knowing what they really are, they make an interesting case to study,...

Initially published as a Gem note in the Journal Of Gemmology of the Gem-A. 2019, 36(8), 688–690. http://doi.org/10.15506/JoG.2019.36.8.688 Enstatite may display asterism with four, six or eight...

Recently, a kind of gray 'sunstone' entered the market, it is offered either as a sunstone, an aventurescent feldspar or the most frequently as an aventurescent quartz included of graphite. The gemstone...

Initially published as a Gem note in the Journal Of Gemmology of the Gem-A. 2019, 36(6), 501–503. http://doi.org/10.15506/JoG.2019.36.6.501 Hydroxylherderite [CaBePO4(OH,F)] is a phosphate mineral...

Zircon comes in all colors, violet, purple, blue, green, yellow, orange, red, pink and brown as well as colorless. Seen for the first time, the described zircon exibits an unusual hazy white color as...

Poudretteite is an extremely rare mineral and gemstone that was first discovered as minute crystals in Mont St. Hilaire, Quebec, Canada, during the sixties. The mineral was named for the Poudrette...

The Valzergues fluorite mine is famous among European collectors for its fabulous specimens of brigh yellow, sometime almost orange, gemmy fluorite in large cubic crystals up to 30 cm and clusters...

Dumortierite is a fibrous variably colored mineral, from brown, blue, and green to more rare violet and pink. This aluminium boro-silicate (Al,Fe3+)7(SiO4)3(BO3)O3, crystallizes in the orthorhombic system...

Cancrinite is sometime found as a gemstone but more commonly as a mineral specimen. It occurs in many colors such as blue, grayish-green, yellow, orange and reddish. Prismatic crystals are rather...

Brucite is mainly a collector's mineral composed of magnesium hydroxide. It occurs in various colors as white, gray, grayish-blue, light-green and more recently as deep yellow (lemon-yellow). Around 2015, maybe...

Legranddite named after M. Legrand, a Belgian mining engineer, was first described in 1934 for an occurrence in the Flor de Pena mine, Nuevo Leon, Mexico. It is a rare zinc arsenate mineral,...

Sunstone is well known by gemologists, especially the orange varieties from India and Tanzania, another source is Oregon in USA that produces a red sunstone. The sunstone is an aventurescent...

Sphalerite is a zinc sulfide mineral with a chemical composition of (Zn,Fe)S, ideally ZnS. It is found in many parts of the world and is the most commonly encountered zinc mineral making it the...

Amethyst is the purple color variety of crystalline quartz and is the most popular gemstone from ages past. Even if the definition gives purple as the color (with various saturation, from very light to...

The Kukh-i-Lal mines (formerly the ‘Badakhshan ruby mines’) are located in what is today Tajikistan. Up to the end of the 20th century, little was known about these mines located in a closed area of...

Graves Hill is a very popular fossicking area located in Central Queensland, Australia. It is situated about 4 km west of Sapphire township and 10 km south of Rubyvale. It is famous for its shallow...

For most of people, fine emeralds are sourced in Colombia. Brazil appears to be another important source for emeralds, mainly for mid-grade product. Since 1976, large scale emerald mining began in...

Since mid-2001, attractive crystals of demantoid have been mined from the Kerman province in southeastern Iran. The mines are located nearby Soghan city and especially in the moutains close to Bagh...

The Peñas Blancas mining area is located near the Mun. de San Pablo de Borbur, in the Vasquez-Yacopí Mining District, Boyacá Department, Colombia. It is on the northern edge of the western emerald...

The two cut stones (figures 1a, 1b) were faceted from crystals bought to be orange kyanite from Loliondo in Tanzania,  then identified as orange sillimanite. Such orange color is unexpected for...

Green kyanites are quite rare especially the yellowish-green ones, the 10.15 ct sample presented here is reportedly from Mirerani (Merelani) in Tanzania. It should be noted that such a 'big' kyanite...

A new find of sapphire in Ranotsara, in the south of Madagascar, reportedly unheated after the miner. The gemstone, figure 1, is bluish-purple while viewed down to the table but pinkish-purple other orthogonal...

The bluish-green material as shown in figure 1 was sold as chrysoprase from Haneti, Kondoa district in Tanzania. Chrysoprase and prase opal are quite similar in appearance but gemological properties...

Yet another kind of material coming from the former province of Khorassan in Iran as the gem-silica type described in 'greenish-blue chalcedony, a "gem silica" from Khorassan, Iran'. This is a...

Green kyanites are quite rare, the yellow ones are even rarer, the 7.69 ct sample presented here is reportedly from Madagascar but because of its Mn content it might be coming from Tanzania as for the...

Gem silica has become in the past years a prominent gemstone in the market, at least the demand is quite height. Gem silica is the trade name for a rare gemstone with a vivid bluish-green to...

This 0.70 ct colorless gemstone (figure 1) was expected to be nosean or analcime as it is sold in Thailand for some time now. Such a size of such transparency analcime is uncommon and it is the same...

This 3.43 ct yellow apatite was submitted as a yellow tanzanian danburite. The color / hue is well saturated and even if the gemstone had a quite deep pavilion, the cut performs well in returning the...

Vesuvianite, also known as idocrase, is a green, brown, yellow, or blue sorosilicate mineral. Vesuvianite occurs as tetragonal crystals and its chemical formula is Ca10(Mg,...

A small mint-green chrysoberyl, figure 1, was sold as a vanadium-bearing chrysoberyl because of its Tanzanian provenance. Vanadium, chromium / vanadium -bearing chrysoberyls have been found in...

This 10.14 ct natrolite crystal supposedly originating from Mwanyanga, near Comolo, Arusha, Tanzania was donated by . Natrolite is a tectosilicate mineral species belonging to the zeolite subgroup...

A small dark violetish-blue sapphire with a strong color saturation weighing 0.84 ct has raised a lot of questions. Especially the question to know if this sapphire is a natural or synthetic one.  This...

Uranium glass is glass which has had uranium (U), usually in oxide diuranate form, added to a glass mix before melting for coloration. The proportion usually varies from trace levels to about 2% by...

Such 'vivid' sky blue color results from heat treatment of brown zircon found in the province of Ratanakiri (also spelled "Rattnak Kiri") in the extreme northeastern corner of Cambodia. There are some...

The turquoise is usually sky blue (most desirable as a gemstone), blue, blue green. The green turquoise is rather uncommon and the color is mostly 'strongly bluish green'. The stone is sold as a...

Two cabs of a white material with strong blue veins and few green veins, reportedly from Arizona, USA, weighing 8.95 and 5.37 ct, are studied in this report. As it can be observed on figure 1, the...

Agrellite is a very rare mineral found in mafic, sodium-rich and silicon-poor igneous and metamorphic rocks. It is only found at a few locations including the Sheffield Lake complex, Kipawa River,...

This scapolite was found on the internet and sold as a "Peach color scapolite with a color change", it is reportedly coming from Pakistan. The overall color is light yellowish brown but because of the...

Grandidierite was an extremely rare mineral that was first discovered in 1902 in southern Madagascar. The grandidierite has already been described from several locations: Madagascar[1][2], Sri Lanka[3], New...

This crystal of sanidine, a potassic feldspar, comes from the Uhuru peak, the highest summit on Kibo's crater rim of the mount  Kilimanjaro in Tanzania. Kibo is one of the three stratovolcano of the...

  Photo 1: An unusual facetted 8.60 ct black amphibole. Shape cushion Size 13.2 x 12.6 x 7.2  Color black Lustre vitreous Weight 8.60 ct SG 3.08 RI 1.631 - 1.655 DR 0.024 B+ Pleochroism - Polariscope /...

In the late 2013, so particular greenish-blue kyanite appeared in the market, reportedly coming from the Odisha state of India (the former Orissa indian state). The kyanite (figure 1) has an unusual...

The 3.54 ct gemstone described in this work was studied along with two other gemstones with fully identical properties and spectra, they were just smaller with a weight of 2.06 and 1.52 ct. They all...