Have you ever wanted to date a site by the glass lying on the surface?

This is a topic I have had on the back burner for awhile now....

Then the other day while I was digging a hole to retrieve a .58 caliber 3-ringer bullet I dug this bottle neck....


Then the thought came back to me about dating a site with glass....I knew when I saw this neck out of a Flask that it dated right around the Civil War era...Actually it's a dead 1850-1870 time frame for that style of applied ring lip...They liked to flatten the glass down to make the ring flat in that period...

So theres a very good indicator of the site's age without even seeing a metallic artifact...

you can use non metallic pieces to quite accurately date a site if you keep your eyes open...Pottery,ceramic's, And glass will date a site...even marbles...

I like glass mainly because I have collected bottle since the age of 5 years old...So I have a certain fascination with it...And a site is easily dated when a few pieces are picked up and analyzed...to build a time span picture...

In the united states on pre civil war site's especially the colonial and federal period sites when you encounter thick shards of black looking non see through glass it is a very very good indicator of pre civil war sites....if you are lucky enough to find the necks they date the site better...


These style necks are a good 1820's-1840's style...earlier like pre 1800 will get more stringy type lips as they work there way back to the 1700 era..

Post civil war sites will hold more clearer type bottles that will be the most common like Medicine bottles and such...alot of the glass is going to be an aqua or light green...the glass color comes from the iron oxides in the glass....

Glass can be made to be clear even back in the 1700's ...but to get it clear flint had to be crushed and added to it and it was expensive and reserved for table ware like wine glasses and such...In the 1800's lead was added to glass to make it clear..

But begining in 1880 through 1914 manganese was added to glass to make it clear for like medicine bottle's and food contianer's...Manganese was cheap so not only the rich could have access to clear bottles but now it was used in common everday glass container's...

Whats special about manganese being used? Well when it's added to glass to make it clear it also does something weird when it's exposed to U.V. sun ray's.It turns the glass pink or amethyst...What good about that.. well the glass lying outside will turn color and when you see pink glass you know the site is dated 1880-1914...Good site for barber coins and even late seated is it not?might want to hunt it extra hard...dont let the wheat penny's fool you theres older money in here....!!!!

Heres some pink shards I have picked up.



But the story is not over yet.....the manganese was stopped but then selenium was started from 1914-1945..
Whats good about selenium?It turns glass thats exposed to u.v. a brown straw honey color...
so theres another site dater...up till the end of WW2..
Heres a piece...


Necks are also a good way to date glass if it's of the aqua or greenish tint color's thats the most common through the 1840's till the 1920 or so time...
Alot of the glass will have a tooled lip from civil war till automatic bottle making machine's came into use in the early 1900's...
Medicines will have a lip like this through the last half of the 19th century..


a bottle that has a ponitl scar on the bottom will usually date pre civil war ..after the civil war bottles were held with a set of special built tongs ...before that the bottle was held with a molten piece of glass while the neck was being finished after removal form the blow pipe...
Heres a pontil scar on pre civil war bottle...


you see the bottom of bottles with that jagged piece of glass on the bottom they are pre civil war ...

after 1900 the owens automatic bottle machine was invented ...so no more mouth blown bottles no more hand tooling the lip's...
How can you tell...well the glass for one thing is really uniform with no air bubbles perfect symetrical style...and the mold seem goes all the way up the side and across the top of the lip....

One thing that is unique is the Crown cap was invented right before the owens machine was invented ...they actually hand blew bottle's like thay had for hundred's of year's then had a crown tool to make the top... the hand applied crown top only lasted about less than a decade..So if you find a crown cap bottle but no mold seem across the top it's about 1895 till about 1905..the crown cp is still in use today,made by machine unchanged for 100 years now..
heres one I dug that dates to the hand applied window of time...


looks alittle cruder than the regular soda's...

and heres a soda top from about 1840 till crown cap....They call these blop top soda's,they evolved for 70-80 years but were very similar..


All questions will try to be answered on dating glass.Fire away..

Keith



Edited 1 time(s). Last edit at 11/25/2012 07:32AM by Keith Southern.

Great information!



Edited 1 time(s). Last edit at 11/25/2012 10:36AM by Crosby.

I'll have some questions when I get around to digging a big bottle dump from the old homesite whee I found the Eagle Martingale. Alot of cork type bottles just sticking up out of the ground!!! Along with brown cans that are so rotten than when ya try to lift one out, it falls to pieces. That is some interesting stuff, Keith!!!!

One thing I want to add...Is plowed fields are great places to look for non-metallic dater's....that light stuff floats to the top after the ground is distrubed,,

You can ride down a road and look into a plowed field with the sun to your back and see the glass twinkling a hundred yards away...

Use your 6th sense...

if you see alot of pink glass and straw brown type glass mixed you know the site is a site that could very well be the best spot to find a 1916 D mercury with not alot of wear...

it does not mean one is there by no means but your odds increase when you are in the right era...

in other words learn to date a site for the objects you want to dig the most...If you really want a certian dated coin your odds will increase tremendously if you are on the exact era ground it could of been dropped when new...no wear,or minimal wear...

Keith

Thank you Keith. Very good data.

That's some really valuble and interesting info Keith! Im always running across old glass/ bottle shards but knew very little a out them. I have saved some of them, I'll try finding them.

How about peices of china from plates w colors on them, I have saved alot of those from a couple really old sites. Can you do a peice on that too?

Thanks for posting!

Very interesting Keith....don't know beans about bottles and glass but indeed the dirt and above all the grass you are hunting can tell you a lot and don't forget them bare spots with no grass as everyone sems to hunt the grass and leave a goodie or two for those that investigate.

Thanks Kieth, I had been guessing about the age of that pink tinged glass. I assumed it was from the turn of the century. Looks like I was right. Great info, answered a lot of questions.

Yall are welcome....I hope it helps people to get their minds to thinking....Pink glass will hold some nice coins.....Barber halfs with liitle or no wear...Good spot for morgan's also...

Yes Jerry your time line for pink glass was right on...Usually bad for civil war relics but good for coin's...But most of my spots with pink glass have more indian heads than any thing else...LOL!!

Aaron..Yes a site can be dated with china but not as accurately I have found as the small windows of evolution of bottles can date more precisely...I do like to look for feather edge china when looking for civil war site's and earlier......
you cant miss old artifacts if the site has this type china..it was in use from about 1790-up till civil war...very common type china to look for ..just about everyone in that time period had this simple style...


Post up some pics of the glass Aaron...we can try and date it..

Keith

Keith --

One of the most interesting, informative, and educational posts I've read in quite awhile. And, not surprising, since you seem to post alot of these super-informative posts...

THANKS!

Steve

I also pull up glass and more so, pieces of china. Pieces of brown pottery have been coming up, and I don't think it's pieces of clay pipe. Great post Kieth. That knowledge will come in handy and makes the hunt more fun.

Great post Keith. I love them bottles too,been a while since I've hug em

Thankyou Keith for a very informative post. I've been inadvertently collecting bottles for decades while prospecting silver here in Ontario. Sometimes we come across old dilapidated cabins or their remnants and usually find old bottles, clear, aqua (sauce or medicinal types sometimes with writing on them), yellow (which I thought was related to sodium in the glass), and of course the manganese purple ones on the downhill side of these sites. I use metal rods to probe down through the leaf mould and soil trying to feel that glass "tingle" and dig carefully. Many are broken but some are pristine-looking after a soak, scrub and wash. Most also are replete with air bubbles.

What a timely post Keith... I had read an excellent review of this subject about 20 years ago in W/E Treasure magazine and kept it for years on file. I mistakenly gave it away with other W/E Treasure magazines to a young fella just entering the hobby a few years back. Thanks again... it certainly is good to know we have some expertise on the subject here.

Jim.

That is some very good information there!

There are certain shoreline locations where a lot of glass washes into around the San Francisco bay. A couple of weeks ago, I found a very odd looking light green bottle that washed up on a beach, but threw it away without thinking.

But now, going to be a little more observant and aware of some of the characteristics of old bottles.

Thanks for the post.

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