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.

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

Calcite II – Jewelry & Art

In this blog, art works and jewelry, dating from 2300-2400 BC to the present, are shown. All were discovered with great fun by googling the web. CALCITE JEWELRY AND ARTWORK REFERENCES Ref 1. https://www.metmuseum.org/art/collection/search/543887?rpp=30&pg=2&gallerynos=103&rndkey=20150416&ao=on&ft=*&pos=55 Ref 2. https://www.penn.museum/collections/object/293415 Ref 3. https://www.dia.org/art/collection/object/canopic-jar-human-head-cover-43587 Ref 4. https://en.wikipedia.org/wiki/Canopic_jar Ref 5. https://www.pinterest.com/pin/300333868875258132/?lp=true Ref 6. https://www.brooklynmuseum.org/opencollection/objects/3594 Ref 7. https://www.pinterest.co.uk/pin/386605949244823995/ Ref 8. https://www.mfa.org/collections/object/hadrian-58915 Ref 9. http://www.britishmuseum.org/research/collection_online/collection_object_details.aspx?objectId=479257&partId=1 Ref 10. https://www.alamy.com/disk-brooch-late-7th-century-frankish-gold-sheet-with-copper-alloy-backing-and-inlays-of-garnet-glass-and-calcite-overall-2-14-x-1516-in-57-x-24-cm-metalwork-gold-the-dress-of-frankish-women-generally-consisted-of-a-tunic-cinched-by-a-belt-from-which-hung-an-array-of-pendants-a-wrap-or-cloak-went-over-the-tunic-shoes-and-hosiery-fastened-with-buckles-covered-the-legs-image212485417.html Ref 11. https://www.ebth.com/items/9279883-mexican-made-sterling-silver-calcite-brooch-and-earrings. . . Read More

Calcite I

Despite its wide distribution in limestone and as a common gangue mineral in ore deposits, the rainbow of colors and beautiful crystal forms of calcite, from locations around the world, have made it a favorite of collectors. One such favorite is the group of calcite crystals, tipped by hematite, from the Egremont Mine shown in. . . Read More