Gemology Hub | Gemstone & Mineral Identification Guides

💎 Gemology Quiz 1. What does gemology study? The study of rocks only The study of gemstones and their properties The study of fossils 2. Who is a gemologist? A person who mines gemstones A person who designs jewelry A person who identifies gemstones using instruments 3. Which of the following is NOT a characteristic of a mineral? Naturally occurring Organic in nature Has a defined chemical composition 4. What makes a gemstone valuable? Only its size Beauty, rarity, and durability Color only 5. Which of the following is an organic gem? Sapphire Pearl Emerald 6. The Mohs scale measures what property? Toughness Hardness Transparency Submit Quiz

  Introduction: A light purplish-blue sapphire weighing 15.84 carats was submitted to the Laboratoire Français de Gemmologie (LFG) for testing. This stone turned out to be a synthetic sapphire , but what made it especially interesting was the presence of Rose channels — a feature usually seen in natural sapphires . What Are Rose Channels? Rose channels are tiny hollow tubes inside the sapphire that always appear at the points where twin layers (called " twin lamellae ") meet. These channels are positioned along the edges of certain crystal faces and form angles of about 90 degrees. Normally, these are features of natural sapphires. Why Is This Discovery Important? These channels and twin lines are common in natural sapphires , but very rare in synthetic ones . However, this sample — a Verneuil flame-fusion synthetic sapphire — had both features clearly visible. It challenges the assumption that Rose channels prove a gem is natural. Other Findings from Testing: Under...

What Are Negative Crystals in Gemstones? Negative crystals are tiny, hollow shapes that form inside gemstones. These shapes look like small crystals and can be filled with liquids, gases, or other materials. Scientists have studied these crystals to understand how they form. How Do Negative Crystals Form? Negative crystals can form in two main ways: Healing Cracks: When a gemstone gets a crack, it may come into contact with water or other liquids. Over time, the crack begins to heal, and tiny hollow shapes form. These are called secondary negative crystals. Scientists have observed this process by heating synthetic rubies with cracks. The heat helps the healing process, forming these small, hollow crystals. During Growth: Sometimes, negative crystals form as the gemstone itself is growing. These are called primary negative crystals. They usually appear alone and are larger than secondary ones. Different Types of Negative Crystals In Synthetic Gemstones: Scientists found that heating s...

Corundum MCQ Quiz (50 Questions) Corundum MCQ Quiz (50 Questions) Submit Answers

Sodalite is a fascinating gemstone known for its vibrant blue hues and unique tenebrescence , the ability to change color under UV light . In recent years, high-quality sodalite (also called hackmanite) has been sourced from Myanmar and Afghanistan . If you are a gem collector , jeweler , or enthusiast looking to understand the differences between these two sources, this comprehensive comparison will help you make an informed choice. 1. General Characteristics Tenebrescence: Both Myanmar and Afghan sodalite exhibit tenebrescence, allowing them to change color when exposed to UV light. Transparency: Afghan sodalite is typically more transparent, whereas Burmese sodalite tends to have more inclusions. 2. Transparency & Clarity Afghan Sodalite: Cleaner, with fewer inclusions and higher transparency . Burmese Sodalite: More included, often with visible fractures and foreign material. 3. Color and Tenebrescence Burmese Sodalite: Usually has a deeper, richer purple or violet co...