Ancient Rubies

In this continuation of blogs about the corundum gem varieties, sapphire and ruby, I will first describe the trade routes that first brought the gems, from their mines in the East, to the Roman Empire, then to the rest of Europe. I will also present a gallery of ruby jewelry and artworks designed and made. . . Read More

HARDNESS: A MECHANICAL PROPERTY OF USE IN IDENTIFYING MINERALS

Along with the colors and crystal forms of minerals, their mechanical properties such as the hardness. tenacity, and habits of structural failure can be very useful tools in identifying an unknown mineral. In this first Blog on the use of mechanical properties in identifying minerals I’ll focus on hardness and describe the Moh’s Hardness Scale,. . . Read More

Sapphire – Art Deco

Art Deco is my favorite style of jewelry with its flair of design and the use of unusual combinations of gemstones.  Art Deco is a style of architecture and design which first appeared in France just before World War I, reaching its high point in the 1925 Paris Exposition of Decorative Arts, and extending into. . . Read More

Corundum – From Sapphires to Rubies

Gemstones of the mineral corundum [Ref 1] offer a rainbow of colors for the lapidarist and jewelry maker as displayed in Figure 1.  Traditionally, of these, the ruby and blue sapphire, along with diamond and emerald, are considered to be the four-membered family of precious gems.  Corundum gemstones, other than the ruby and blue sapphire,. . . 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

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.