Stone? If So, What Kind?

Is this some sort of polished agate? It's a very pale brownish with a milky white streak about 2/3 of the way down.

The setting is sterling. Thanks!

 

My first thought was smokey quartz, but that iridescence in the last shot looks like brown Labradorite or maybe an AB finish?

 

Chalcedony? Chert? Glass?

 

Chalcedony? Chert? Glass?

 

I LOVE the pendant. It looks too cloudy for smoky quartz, then that one angle has an irridensence? The mention of a white line in it has me confused too. I can't see the line you mention?

 

It could be what Bob said,a tan chalcedony, but the white streak? HUMMMMMM?

 

Chalcedony is a generic name given to any material that is composed of microcrystalline quartz. Agate and jasper are both varieties of chalcedony.

What is microcrystalline quartz? “Quartz” is a mineral composed of silicon and oxygen (SiO2) and the word microcrystalline means that the quartz is in the form of crystals that are smaller than 30 microns in size (a micron is a unit of measure that is 1/1000th of a millimeter). These are very tiny quartz crystals – smaller than can be seen by the unaided eye. (Sometimes the word “cryptocrystalline” is used instead of “microcrystalline.”)

Chalcedony is a very hard material. It has a hardness of 7 on the Mohs scale. It breaks with a conchoidal fracture, and freshly broken pieces have a very smooth, non-granular texture and a waxy to vitreous luster. These characteristics enable chalcedony to be cut and polished into a bright, durable gemstone.

Chalcedony occurs in a wide range of colors. It is often gray, white, brown, red, yellow, orange and black, but it can occur in any color. It can also be banded or have plume, dendritic, mottled, mossy or other color patterns. At one time the word “chalcedony” was reserved in parts of the gemstone industry for a light blue translucent material; however, this use of the word has nearly disappeared.

 

Well, if you can't ID the stone, just send it to me

 

LOL SOS.

Hi Everyone, I am just passing through on my lunch break from work, so I don't have time this minute to respond to everyone, but thank you for some suggestions. I will investigate and respond further when I get home.

I just wanted to add this picture to show the whitish spot I'm seeing.

 

No AB finish. I think the iridescence you're seeing is a reflection of the lamp I used - hard to describe, but they have a blue plastic reflector behind the bulbs.

Thanks for the suggestions - it gives me a direction to look.

 

I had a chalcedony brooch recently which was way paler than this and much more matte, but I see SOS says it comes in different colors, so I'll investigate.

And chert I've never heard of, so that gives me another possibility to look for...thank you for the suggestions.

 

For an in depth investigation? LOL.

Off to look at some of the possibilities.

 

Hmm, I was going to say no to smoky quartz as it seems too translucent compared to my pendant (all the examples I saw at first were completely translucent), but then I came across this, so now I don't know....

 

That pendant sure looks like yours. I see the cloudiness in yours now. I Googled does smoky quartz have white inclusions, and came up with this. I didn't read it all but this popped out.
"Sometimes inclusions cause the formation of phantoms. Here the quartz crystal might have been partially encrusted by another mineral when growth halted transiently and continued later, such a case could be considered a syngenetical formation that got overgrown."

http://www.quartzpage.de/inc_text.html

 

Of course all gem stones have inclusions, like the black spots in low grade diamonds, I guess I was looking for cloudy inclusions?

 

Interesting.

Yes, that one I showed above sure looks similar to mine. I'm going to go with smoky quartz I think.

 

Its really glass so you better send it to me

 

Some lower grade moonstones look like that too, as will some agates. My first response was "moonstone" and then when I saw the stripes "banded agate". You pays your dollar at the yard sale, you takes your chance.