A Short History of Emeralds

The emerald is the chromium-containing variety of the mineral beryl [Ref 1]. Its’ beautiful, vibrant, deep green color has made it a great favorite among those that create beautiful jewelry and art works from it, gem & mineral collectors and those who wear it. Witness the Hooker Emerald, set with diamonds, in a brooch, seen. . . Read More

Star Sapphires & Rubies

The star gemstones of the corundum family are either star sapphires or rubies.  Under light these gemstones exhibit asterism [Ref 1] in showing either a six rayed or twelve rayed star.  The starred gems present a beautiful and novel appearance and are highly desired by artisans, those who wear them and collectors.  In this blog I’ll briefly describe what. . . Read More

Diamonds IV

Lattice Defects, Impurities and Color As stated in references 17, 18 of my DIAMONDS II blog, impurity atoms and lattice vacancy defects are responsible for the coloration of diamonds [Ref 1].  A lattice vacancy (V) without a carbon atom in the diamond lattice which partners with one to four neighboring nitrogen atoms (N), in colored diamonds,. . . Read More

Diamonds III

A Gallery of Natural Diamond Crystals The gallery includes clear crystals and those exhibiting a range of colors (Figures 2-13), a range of shapes (Figures 2-15), examples of inclusions found in Diamonds (Figures 1-3), examples of shaping and etching by resorption (Figures 3-15), and examples of twinned diamonds (Figures-14,15).  Well-developed crystal forms, typical of diamonds, are. . . Read More

Diamonds II

In this blog, my second on diamonds, I’ll discuss the physical and chemical properties of a diamond, then its optical properties in relation to its crystal structure and chemistry, and then their formation and associated geology.   CRYSTAL STRUCTURE AND PROPERTIES OF DIAMOND To understand the physical properties of the diamond it’s important to understand its. . . Read More

Diamonds I

Having greatly enjoyed writing my last blogs on garnets as gemstones and mineral specimens, topics different from my long-time interests in the ore-forming minerals, I am starting a series of blogs in the same vein on the precious gems: diamonds, emeralds, rubies, and sapphires.  In the first three blogs the topic is diamonds.  In this first. . . Read More

Fluorite Art Works & Jewelry

Artworks and jewelry have been created from fluorite since ancient times, such as the carved fluorite statues discovered in Crittenden County, Kentucky and shown in Figure 1 [Ref 1]. The statues reflect the Middle Mississippian Culture extending approximately 800 Ad to 1600 AD. The second statue from the left, known as the Tolu Statue is. . . Read More

Fluorite, A Collectors Favorite

The rich, often “electric” rainbow colors of fluorite specimens from world-wide locations, the frequent appearance of different colors within regions, bound with the lattice planes within a crystal, and the sculptural appearances of stepped cubic and octahedral crystals, as shown in Figures 1-5, make fluorite a favorite among collectors.  In this blog I’ll describe those. . . Read More

Fluorite, A Gallery of Specimens

I’ve assembled a gallery of 15 fluorite specimens from some of the locations around the world which are favored by collectors.

An Unusual Quartz Crystal

While at the Flagstaff Gem, Mineral & Jewelry show this past August, my fellow Coconino Lapidary Club member and collector friend, Gordon, and I spotted an unusual appearing polished quartz crystal. Upon closer inspection we spotted a geometrical array of fine lines within the crystal which looked to be perpendicular to each other. The appearance. . . Read More