USES OF CLEAVAGE, PARTING, AND FRACTURE IN MINERAL IDENTIFICATION-I

Structural failure of a mineral crystal can occur by cleavage, by parting, or by fracture.  The characteristics of any of these failure modes exhibited by a mineral can be useful as tools towards its identification. In this Blog I’ll discuss the properties of cleavage and their use in identifying minerals and follow with a second. . . Read More

GALLERY OF CHINESE CARVED JADE ART

To the great advantage of the beauty of their art, Chinese carvers of jade were guided by themes and decorative motifs in the shaping of their carvings and the choices of decorative motifs adorning them[Ref1-7].  In the Neolithic Era of China ritual jade carvings found in burials reflecting the cosmology of the heavens and the. . . Read More

HISTORY OF JADE CARVING IN CHINA

From the late Neolithic Age (circa 3500 BC-2070 BC) into today the crafting of jade art objects in China has produced beautiful and magnificent art objects which exhibit remarkable diversity of both color and form as shown by the carved nephrite jade pendant with phoenix pattern and the funerary Bi Disc with rain pattern in. . . Read More

MINERAL STUFF: THE GEMSTONE JADE

Since ancient times jade[Ref1] has been used by artisans to create beautiful jewelry and works of art. Art objects of jade have been carved in China for more than 6000 years[Ref2] as exemplified by the jade dragon carved during the Zhou Dynasty (5th – 4th century BC) as shown in Figure 1. In Central America,. . . Read More

PALEONTOLOGY OF AMBER

In this Blog I’ll describe how biomaterials including animal and plant fossils are included and preserved in amber formed from tree resin, which by its stickiness can entrap objects which contact its surface as shown in Figure . With further addition of the resin the object is sealed within the resin and out of the. . . Read More

MINERAL STUFF: AMBER, THE GEM

Amber is a hard resin formed from tree sap by fossilization and is many millions of years old[Ref1]. Since Neolithic times (about 9000-3000 BC) and before the Copper Age[Ref]2) amber has been highly valued as a gemstone and used to create beautiful jewelry and artworks. Wide use of amber in Early Europe and in the. . . Read More

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