The Roman author, Elder Pliny, explains the invention of glass in his writings Natural History.  "A trading ship carrying nitrum anchored (off the coast of modern Lebanon); its crew went ashore to prepare their dinner.  Finding no stones on the beach with which to prop their cooking pots over the fire the sailors used lumps of nitrum from their ship to support their cookware.  When these became heated, they combined with the sand from the beach to form a 'strange liquid that flowed in streams; and this, it is said, was the origin of glass.'"1  The basic science behind this phenomenon described by Pliny is the mixture of silica (pulverized quartz or quartz sand), nitrum (basically soda) and lime (most likely also contained in the beach sand).2  Early Celtic glass was most likely prepared in this simple manner.  The knowledge behind the combination of ingredients for the production of glass did not however, occur quite as haphazardly as Pliny suggests.  It originated farther east than the shores of Lebanon, in the ancient country of Mesopotamia during the third millennium BC, where the recipe was written on clay tablets in cuneiform script.3  The knowledge of glass making made its way through history and was probably passed on by way of Phoenician traders to early continental Celtic tribes.  Either creating their own glass from raw materials, importing raw glass from Greek city states, or melting down imported glass trading vessels (perhaps those that carried wine from the south), the Celts began to incorporate this new medium into their artistic repertoire. 
    The difficulty in fashioning glass artifacts, producing raw glass or the expense of importing raw glass lead to a very centralized craft production and distribution.  "Evidence suggest that the manufacture of glass objects was amongst the most centralized and specialized of any of the branches of craft production in the late La Téne period."4  Localized glass production meant that larger oppida would contain a majority of glass artifacts.  Major glass working oppida during the La Téne period were: Stradonice, Staré Hradisko and Manching.  Peak glass production occurred during the late La Téne C2 and D periods.5
    Most glass artifacts dating to the Celtic La Téne period were core formed or rod formed.  Core formed objects were made by molding molten glass around a removable core or center.  This core usually consisted of a combination of dung and clay mixed with water, so that it may be shaped and attached to some type of metal rod.  The core was then covered with glass and shaped in a kiln using the metal rod and other tools.  Patterns and colors were added to the artifact using the rod forming method or a variation thereof.  This method was most commonly used in the production of glass beads.  In the rod forming technique, a glob of molten glass is attached to the end of a rod.  The glass is then heated in a kiln until it is malleable.  At this stage the glass can be shaped into a bead or other object.  To apply patterns or other colors to either rod formed or core formed artifacts, glass of another color is attached to the rod, heated and then drawn out and around the object (in the case of spirals for example) or pressed onto the object (as in the case of circles or dots).  The entire artifact can be reheated and reworked numerous times to create complex patterns and combinations of colors.  [This section on glass forming techniques was demonstrated and developed by Bill Gudenrath in Harry Abrams: Glass 5,000 Years pgs. 214-6]
    Common Celtic patterns employed in the creation of glass artifacts are for the most part very simple and geometric.  Inclusion of these on glass objects may have been believed to enhance the properties of the glass itself.  These patterns are most apparent in glass beads.  One of the most widely used is the spiral pattern.  Since prehistoric times spirals have been associated with death.  They may have also been used as solar symbols.  Almost, if not as common as spirals are patterns consisting of concentric circles.  These resemble eyes and may have been used as protection against misfortune; as in the 'evil eye.'  Triskels, s-scrolls, running-dog patterns, and chevrons (all indicators of the La Téne style) are also quite commonly found among Celtic glass artifacts of the time. 
     Glass, as a material, had special meaning for Celtic tribes.  Early on this new product was of great value not only because of its scarcity but because it resembled semi-precious stones.  Most scholars agree that  the wide variety of colors found in glass are the result of producers attempts to copy those stones.  This new glass material also resembled amber, which traditionally had 'magnetic power.'6  The similarities among semi-precious stones, amber and glass and well as the scarcity factor endowed glass with 'magical' properties for Celtic tribes.  The shaping of glass and the addition of patterns enhance these qualities; thus glass begins to be incorporated and used for adornments in Celtic societies.
    In the preparation of this small catalogue the portrayal of a variety of uses for Celtic glass artifacts is attempted.  Included in the catalogue are entries for beads, bracelets, gaming pieces, cult objects, and necklaces.  Glass beads are the most common surviving of the artifacts.  Their size and construction account for much of this survival.  During the Roman period some beads were used for votive purposes at sacred shrines, wells and temples. Of note here, the temples were of both Roman and pre Roman Celtic types.7  A major use for beads was in the crafting of brooches.  Often brooches were worn in pairs on the shoulder region and connected with strings of beads.  A string of 176 beads found on a site in Essex, England was used to connect two two gilt bronze saucer brooches.8  Several other brooches also from the site were found to be connected with strings of beads.
    The discovery of glass within a grave context seems to be quite a factor in determining the nature of who is buried in the tumulus or grave.  More often than not, skeletal remains dating back to this period are completely destroyed by acidic soil; all that is left is a silhouette of noticeable chemical compounds left by the body.  Usually when glass is found at these or any site where the sex of the skeleton is unknown, the prognosis is female.  M.U. and W.T. Jones write "Beads as well as brooches are the principal indication of a woman's grave," in reference to their analysis of excavations at Mucking, Essex, England.9

Glass jewelry played a part in the identification of the Rheinheim "Princess" tumulus in southern Germany.  "As the body had been buried with 13 glass beads the opinion has been that the deceased was a girl," states Tove Hjørungdal in A Gender Critical Perspective.10
 
 

1.  Abrams (1991) pg. 21
2.  Abrams (1991) pg. 8
3.  Abrams (1991) pg. 8
4.  Gebhard I pg. 112
5.  Cumberpatch pg. 67
6.  Guido (1978) pg. 22
7.  Guido (1978) pg. 38
8.  Jones (1975) pg. 182
9.  Jones  (1975)pg. 183
10.  Hjørungdal pg. 23
 

List of Pictures and Credits:

Photographs of "Raw Glass" page 1:  plate 61, DerGlasschmuck Aus Dem Oppidum Von Manching.
Diagram of Necklace on "Bead" page 2:  plate VII, Corpus of Celtic Finds in Hungary.
"Glass Dog" page 3:  Image #216373, Celtic Art & Cultures (website)
"Princess" Rheinheim Necklace page 4:  _____? (website)
Fragments of "Armlets/Bracelets" page 5:  plate 6 pc. 101, plate 39 pcs. 506a and 506b, DerGlasschmuck Aus Dem Oppidum
    Von Manching.
Welwyn "Gaming Pieces" page 6:  plate 71, Glass 5,000 Years.
Bibliography:

Guido, Margaret. (1978).  Prehistoric and Roman Glass Beads in Britain and Ireland.

Abrams, Harry N.  (1991).  Glass 5,000 Years.

Cumberpatch, __________? pgs. 65-8.

Cunliffe, Barry.  (1978).  Hengistbury Head.

Gebhard, Rupert. (I) 'The Celtic Oppidum of Manching and its exchange system,'  Iron Age in WesternEurope, pgs. 110-2.

Gebhard, Rupert. (II) (1989).  DerGlasschmuck Aus Dem Oppidum Von Manching.

Hjørungdal, Tove.  'Early Iron age in Western Europe: A gender critical perspective,'  Iron Age in WesternEurope, pg. 23.

Jones, M.U. and W.T.  (1975).  'The crop-mark sites at Mucking, Essex, England,'  Recent  archaeological excavations in
    Europe, pgs. 133-187.
 
 

Note for Dorothy:
I haven't had a chance to put in the bibliography page here at the end of the essay.  I was also wondering if you had any suggestions on how to wrap this up --it feels fairly disjointed when I read it back to myself.  There are also a few loose ends to be tied up in a couple of the catalogue entries, i.e. crediting the pictures as well as a few quotes.  I'll try to include some in-line text links to the ages from this main essay, but. . . Hopefully I'll have all that done by Wednesday for our get-together.
Thanks,
Jason