|
Assorted Agate Rings
These are agates that I either couldn't identify, or I only had one or two of. Agate
is a common semiprecious silica mineral that has long been used as a gem and ornamental stone. Agate is the most common variety
of chalcedony which is a form of quartz. Agate is, in fact, identical with quartz in composition and physical properties.
Composed of silicon dioxide (SiO2), it has a hardness of 7, a glassy luster, a conchoidal fracture, and a specific gravity
of 2.60.
Most agates occur in cavities of eruptive rocks or ancient lavas.
These agates have a banded structure, successive layers being approximately parallel to the sides of the cavity. During crystallization,
the colored bands are not disturbed. Varieties of agate are characterized by peculiarities in the shape and color of the bands,
which are seen in sections cut at right angles to the layers.
Agate forms when gas bubbles trapped in solidifying lava become
filled with alkali and silica-bearing waters, which coagulate into a gel. The alkali attacks the iron in the surrounding lava,
and bands of the resulting iron hydroxide are created in the gel, which loses water and crystallizes, leaving the bands intact.
Many agates, when cut in cross-section, reveal striking patterns.
|
|
|
| Click on photo to enlarge in new window. |
|
This is a 5x15 freeform I cut from the edge of a piece of something that I can't remember. It may have been off
the edge of a slab of Mexican crazy lace. Anyway, it's mostly translucent with a pinkish color, and a small fortification
pattern on one end. Very interesting and unusual stone, bezel-mounted on a highly polished size 8 sterling silver band.
|
|
|
|
|
| Click on photo to enlarge in new window. |
|
This 8x10 somewhat oval stone has beautiful bands of white and light purple. The stone looks a lot darker in the
photo than it does in reality. Still, it's a fantastic stone, and I wish I had more of this rough to work with, but
I only had a few very small pieces. I have know idea where this agate originated from, so if anyone has any ideas, please
let me know so I can try to locate more of it! This cab is bezel-mounted on a size 10 hammered sterling silver
band.
|
|
|
|
|
| Click on photo to enlarge in new window. |
|
Here's another cabochon of the same material as JRAA002, but this photo shows the true colors better. However, this cabochon
doesn't have the rich purples that the previous one does. This 10x19 freeform is set in a custom made bezel cup and and mounted
on a pure sterling silver size 6½ split shank ring.
|
|
|
|
|
| Click on photo to enlarge in new window. |
|
My daughter calls this light brown agate "root beer stone." I set this 6x8 oval cab with a sterling silver flower accent
and placed it on a size 6 fancy handmade bezel that connects as a band on one end and as a split shank on the other.
|
|
|
