Double Refraction Explained: Birefringence, Identification, and Mineral Examples

by Gelogia Team | Jun 28, 2026 | Mineralogy

Double refraction, also known as birefringence, is one of the most important optical properties used in mineralogy and gemology. It occurs when light entering certain minerals splits into two separate rays that travel at different speeds and in different directions....

Refractive Index in Minerals Explained: Measurement, Identification, and Examples

by Gelogia Team | Jun 28, 2026 | Mineralogy

Refractive index (RI) is one of the most important optical properties used in mineralogy and gemology. It measures how much light slows down and bends as it passes from air into a mineral. Every transparent or translucent mineral has a characteristic refractive index...

Optical Properties of Minerals Explained: Types, Identification, and Examples

by Gelogia Team | Jun 27, 2026 | Mineralogy

The optical properties of minerals describe how minerals interact with visible light. These properties include color, luster, transparency, refractive index, birefringence, pleochroism, fluorescence, and optical phenomena such as iridescence and chatoyancy. Because...

Radioactive Minerals Explained: Properties, Identification, and Examples

by Gelogia Team | Jun 27, 2026 | Mineralogy

Radioactive minerals are naturally occurring minerals that contain unstable radioactive elements such as uranium (U), thorium (Th), or, less commonly, potassium (K). As these elements decay over time, they release radiation in the form of alpha particles, beta...

Fluorescent Minerals Explained: UV Fluorescence, Identification, and Mineral Examples

by Gelogia Team | Jun 27, 2026 | Mineralogy

Fluorescence is one of the most fascinating optical properties observed in minerals. Some minerals appear ordinary under visible light but produce brilliant blue, green, red, yellow, orange, or white colors when exposed to ultraviolet (UV) light. This phenomenon,...