Gemology Hub | Gemstone & Mineral Identification Guides

Gemstone MCQs Quiz Test Your Knowledge in Gemology Part 6 1. A 2-carat fine-quality ruby is worth more than 10 rubies of the same color and quality, which have a total weight of 4 carats . a) True b) False Correct Answer: a) True 2. One carat equals: a) 1 gram b) 1/10 of a gram c) 1/5 of a gram d) 1/2 of a gram Correct Answer: c) 1/5 of a gram 3. A ten-pointer is a stone that weighs: a) 10 carats b) 1/10 of a carat c) 10 facet junctions d) 10 grams Correct Answer: b) 1/10 of a carat 4. When comparing gem prices, you should compare their: a) Per-carat cost b) Overall size c) Density d) Facet count ...

Gemstone Quiz Test Your Knowledge in Gemology Part-5 1. Fancy cut diamonds are those with shapes that are not standard round brilliant cut. True False 2. Alluvial deposits are those in which the gems are mined from soft rocks. True False 3. Which gemstone has a greater range of colors? Corundum Beryl Tourmaline 4. Rubies are sometimes oiled to help mask fractures. True False 5. Ruby can be found in different colours other than red. True False 6. The hardness on the Moh's Scale of spinel is 8. ...

Gemstone MCQs Test Your Knowledge in Gemology Part-4 1. The refractive index of diamond is 2.40. True False 2. Cleavage in gemstones results from directional weakness in atomic bonding. True False 3. Dark field illumination is helpful in observing asterism effect in gemstones. True False 4. A gem material that contains absolutely no transition elements will usually be colorless. True False 5. The Chelsea filter test is especially u...

Gemology MCQs Gemology Multiple-Choice Questions 21. Separating natural pink sapphire from synthetic pink sapphire commonly relies upon a microscopic study. True False 22. In a round brilliant cut, the total number of facets is: 57 59 60 None of the above 23. A spectroscope is used to detect the spectrum. True False 24. Refraction is the bending of light. True False ...

Gemology MCQs Part 2   Gemology MCQ Quiz Test Your Knowledge in Gemology 1. Pink variety of beryl is called morganite. a) True b) False 2. The flashes of color that are characteristic of a diamond's brilliance are caused by a) birefringence b) anisotropism c) dispersion 3. The color of indicolite and Rubylite are usually a) Pink & blue b) Green & pink c) Blue & pink 4. A one-carat round emerald appears larger than a one-carat round sapphire. a) True b) False 5. The specific gravity of Topaz is more than Quartz. a) True b) False 6. A refractometer can be used to measure refractive indices of any polished gem or mineral. a) True b) False 7. Horse tail inclusion occurs in Demantoid garnet. a) True b) ...

Gemmology Quiz Gemmology Theory Quiz 1. Citrine is a) Yellow Quartz b) Purple Quartz c) None of the above 2. Amethyst is a) Purple Quartz b) Yellow Quartz c) None of the above 3. Topaz has a refractive index that is a) High with respect to Quartz b) Low with respect to Quartz c) About the same as Quartz 4. Chalcedony varieties include a) Agate b) Ruby c) Onyx d) a & c 5. Synthetic citrine is difficult to distinguish from natural citrine ...

  Emeralds from Ethiopia Ethiopia , known for being the oldest independent country in Africa and one of the oldest in the world. Its breathtaking landscapes, range from mountains over 4500m high to salt plains 150m below sea level ( Springer ). The beauty of Ethiopia extends to its minerals with opals being one of their most famous gems. Now, with the discovery of emeralds , Ethiopia is now providing an ethical source of emeralds to the gem trade. Emerald Mining Districts The major emerald mining districts in Ethiopia are the Shakiso district in the Oromia region , and the Kenticha and Borena mines . Ethiopian emeralds display a diverse range of colours, including deep green, bluish-green, and sometimes yellowish-green shades. This colour range is determined by the presence and concentration of chromium and vanadium , which gives the gemstone its distinctive green hue. Ethiopian emeralds typically exhibit high levels of transparency and clarity, which enhances their visual ap...

This Mysterious Stone Reveals the Face of an Old Lady – Naturally Formed or Nature’s Art? Discover a rare mimetolith – a naturally occurring stone that eerily resembles the face of an old lady. Nature’s sculpture or just coincidence? You decide Have you ever seen a stone so realistic, it seems like Mother Nature carved it herself? You're about to witness one of the most intriguing mimetoliths ever discovered – a naturally formed chert stone with the astonishing topographic appearance of an old lady's face . This isn’t a sculpture or a manmade carving – it’s 100% natural. What is a Mimetolith? A mimetolith is a naturally occurring rock, mineral specimen, or loose stone that resembles the shape or pattern of something recognizable, like a human face , animal , tree , or even a plant . These fascinating forms are created by millions of years of geological activity, erosion, and mineral deposit patterns. The Viral Stone: A Chert with a Story to Tell The stone in the imag...

 " Yooperlite " is a trade name used to refer to fluorescent pebbles found along the beaches of Lake Superior in Michigan. These unique rocks are a type of syenite containing the mineral sodalite, which exhibits a distinct fluorescence when exposed to ultraviolet (UV) light.  Yooperlite video The term "Yooperlite" pays homage to the residents of Michigan's Upper Peninsula, who are colloquially known as "Yoopers." Using a UV fluorescent light to illuminate these rocks reveals their captivating glow, making them a popular find among rockhounds and collectors.

  Scheelite Information Scheelite is a calcium tungstate mineral with the chemical formula CaWO 4 . It is an important ore of tungsten , used in the production of tungsten alloys and for making filaments for electric lamps . Physical Properties of Scheelite Color: brownish yellow, orange, greenish yellow, yellow, brown, black, colorless Crystal System: Tetragonal Hardness: 4.5 - 5.0 Cleavage: {110} Indistinct, {001} Indistinct Luster: Vitreous (Glassy) Streak: White Transparency: Transparent, Translucent Specific Gravity: 5.9 - 6.1 (Heavy) Diaphaneity: Transparent to translucent Optical Properties of Scheelite Refractive Index: 1.920 - 2.010 Birefringence: 0.080 - 0.090 Pleochroism: Weak Scheelite From China   Occurrences of Scheelite Scheelite is found in hydrothermal veins , granitic rocks , and in skarns . It is also found in contact metamorphic deposits and in high-temperature greisen deposits . It is commonly associated with minerals such as calcite , fluorite , apati...

  Premier Rose Diamond Overview One of the most significant diamonds found in the Premier mine (now the Cullinan mine ) in South Africa was the 353.9 carat (ct) Premier Rose rough .  The diamond crystal was found in 1978 and named after Rose Mouw who helped plan and mark it for cutting.  She and her husband Joe Mouw, owners of Mouw Diamond Cutting Works , purchased the rough diamond and partnered with William Goldberg to cut it into three gems – the Premier Rose ( D-Flawless pear diamond weighing 137.02 ct ), Little Rose (31.48 ct D-Flawless pear diamond), and Baby Rose (2.11 ct D-Flawless round brilliant diamond). The Premier Rose took six months to plan and cut. Specifications Weight: 137.02 carats Cut: Pear Color: D-Flawless Related Topics: What Is A Triple X Diamond? The Secret Behind Investing In These Rare Diamonds ☝ Detecting Treated, Synthetic, Colour- Enhanced and CVD Diamond ☝ USA States Gemstones ☝