Jadeite and Fire-King Identification

Published July 18, 2026 · The Velqo Editorial Team · fact-checked against the sources below

Jadeite identification starts with understanding that the opaque milky-green glass you are looking at could have come from one of three American manufacturers between 1930 and the mid-1970s, and that reproductions began arriving in the late 1990s precisely because the originals had become so collectible. Getting the maker and era right changes the story considerably, whether you are buying, selling, or simply trying to understand what has been sitting in a kitchen cabinet for decades.

To identify jadeite, flip the piece and read the base: McKee used the letters M, C, K inside a circle, Jeannette Glass used a J inside a triangle but left much of its kitchenware unmarked, and Anchor Hocking’s Fire-King line carried embossed FIRE-KING or ANCHOR HOCKING marks that changed over time. The glow test adds a second clue, because pre-war McKee and Jeannette glass contains uranium and glows under a black light while Fire-King jadeite does not.

By the end of this guide you will know the three classic producers and their mark styles, how Fire-King backstamps evolved, why restaurant ware is a category of its own, what UV fluorescence tells you and what it does not, and how to separate old pieces from the reproductions on the market today.

Quick identification checklist

  • Flip the piece and read any mark under strong light: embossed (raised) letters, paper or foil labels, and no mark at all each point to different makers and eras.
  • Look for the maker’s device: M, C, K inside a circle for McKee, a J inside a triangle for Jeannette, and FIRE-KING or ANCHOR HOCKING embossed lettering for Anchor Hocking.
  • Check the base for “Fire-King 2000” or similar modern wording, which marks the commemorative reissue rather than an original.
  • Compare the shade against other pieces in daylight; the makers used different names and slightly different shades of green, so color is a clue and not a verdict.
  • Try a UV flashlight in a dark room; a bright green glow points to pre-war McKee or Jeannette glass, but a piece that does not glow could still be from either maker.
  • Note whether the piece is unusually thick and heavy; that is characteristic of Fire-King’s Restaurant Ware line.

The three classic makers

McKee Glass

McKee, based in Jeannette, Pennsylvania, made the first commercial opaque green kitchenware in this category. The National Depression Glass Association’s history of the McKee jades describes a “Jade Green” in 1930 followed by a slightly darker “Skokie Green” in 1931, and says the jades had a production span of about ten years, mostly in the 1930s. McKee pieces are typically marked with a capital M, small c, and capital K inside a circle, a trademark that appears on nearly every McKee item.

Jeannette Glass

Jeannette Glass Company, also based in Jeannette, Pennsylvania, entered the market in 1932 with a line it called “Jadite.” Its mark is a J inside a triangle, but that mark is comparatively uncommon because much of Jeannette’s kitchenware left the factory without an embossed mark. That makes attribution harder, so the glow test and the shape of the piece carry more weight when a Jeannette-style piece has no mark.

Anchor Hocking’s Fire-King Line

Anchor Hocking is the name most closely associated with the term jadeite among collectors today, and its spelling “Jade-ite” is the hyphenated one. The Fire-King brand debuted in 1942, and Jade-ite arrived in 1945, with the Alice pattern packed as a premium in oatmeal boxes. The original Fire-King production ended around 1976. Fire-King marks are embossed, and a commonly described sequence runs from FIRE-KING with a hyphen, often with OVEN WARE or OVEN GLASS, in the 1940s and early 1950s, to FIRE KING OVEN WARE without the hyphen in the 1950s and early 1960s, to ANCHOR HOCKING added above FIRE-KING from about 1962. Treat those bands as approximate. Some promotional Jade-ite carried no embossed mark and relied on a paper or foil sticker that is usually long gone.

Fire-King restaurant ware and why it matters

Restaurant Ware was a heavy, undecorated line that Anchor Hocking marketed to diners, hospitals, and other food-service businesses beginning around 1948. It is thicker and heavier than the home-use pieces, and it became Fire-King’s best-selling Jade-ite product. That is why so much Fire-King jadeite is commercial-weight tableware rather than decorated domestic ware, and why heft is a clue for Restaurant Ware specifically, not for jadeite in general.

UV fluorescence: a supporting clue, not proof

Uranium was once a common glass colorant, and civilian use was heavily restricted in the United States from 1942 to 1958. McKee and Jeannette used uranium in the 1930s and early 1940s, so their pre-war jadeite glows bright green under ultraviolet light. Fire-King jadeite arrived after the restrictions began and does not contain uranium, so it does not fluoresce.

That makes the glow a useful but imperfect test. A glowing piece points to pre-war McKee or Jeannette glass. A piece that does not glow is consistent with Fire-King, but it does not rule out McKee or Jeannette, because not every piece from those makers glows. Use the glow alongside the mark and the form, not instead of them.

Reproductions and the revival

Interest in jadeite surged in the late 1990s, helped by the collection Martha Stewart showed on television and in her magazines. Two kinds of new production followed, and both circulate widely today.

Reproduction jadeite sold through her Martha by Mail line from the late 1990s was made by companies including L.E. Smith, Fenton (see our Fenton glass identification guide), and later Mosser. Its colorways differ subtly from the originals, but it is made to resemble vintage jadeite, so a convincing shape and color are not proof of age.

Anchor Hocking itself issued a commemorative Jade-ite series in 2000, made from new molds for that year only and backstamped “Fire-King 2000”. Separately, a company called Fire-King Japan began producing licensed pieces around 2010, mixing original American molds with new designs. Those pieces carry the Fire-King name and some use original American molds, but they are new production, not American originals.

To tell reproductions apart from originals: look for “Fire-King 2000” or other modern wording on the base; check for any stickers or stamps that say when or where the piece was made; and compare the shape and the mark against documented originals, since a piece made from an original mold may not give itself away by its form.

Color and form cues

The makers used different names and slightly different shades, and pieces within a single maker’s production also vary, so color is a supporting clue only. Shape often does more work than shade: bowl profiles, canister forms, and measuring cup styles are the way collectors attribute unmarked pieces, which is why matching against documented examples matters.

Watch-outs and common mistakes

  • Not every green opaque kitchen glass is jadeite, and the word “jadeite” is used loosely in resale listings, so it does not guarantee any particular maker or era.
  • Reissues with the Fire-King name are genuine licensed products but are not vintage; read the base for “Fire-King 2000” and compare against documented originals.
  • Reproductions are made to resemble the originals, and some modern production uses original molds, so a good shape alone does not settle age.
  • A piece that does not glow is not automatically Fire-King, and a piece that does glow is pre-war McKee or Jeannette, not a reissue.
  • Surface chips on the rim or foot ring count against a piece; examine edges carefully before purchase.

Photo tips that improve identification

  • Photograph the base mark straight-on with strong directional light to make embossed letters legible.
  • Capture a side profile shot that shows wall thickness, which helps separate Restaurant Ware from lighter domestic pieces.
  • In a dark room, hold a UV flashlight over the piece and photograph any glow for documentation.
  • Shoot the color in natural daylight, not under incandescent or cool-white LED light, which can skew the green tone significantly.

Common questions

How can you tell real vintage jadeite from a modern reissue?

Check the base first: the 2000 Anchor Hocking reissue is backstamped “Fire-King 2000”, and other modern production may carry new maker names or stickers. Then compare the shape and mark against documented originals, because reproductions are made to resemble originals and some modern pieces use original molds. Weight alone is not a reliable test, since the heavy Restaurant Ware originals sit alongside lighter domestic pieces.

Does all real jadeite glow under UV light?

No. Pre-war McKee and Jeannette jadeite often glows bright green because the glass contained uranium, but Fire-King jadeite was made without uranium and does not glow. So the glow is a clue about the maker and era, not a test of whether a piece is genuine vintage, and a piece that does not glow is not automatically modern.

Can unmarked jadeite still be identified?

Often, yes. Jeannette left much of its kitchenware unmarked, and some Fire-King Jade-ite relied on paper or foil stickers that did not survive. Collectors attribute unmarked pieces by matching the form, such as a documented bowl shape, canister profile, or measuring cup style, against marked examples, and the glow test helps separate pre-war McKee and Jeannette from Fire-King.

When to use the Antique Identifier app

Photograph the whole piece on a neutral background, then take a tight shot of the base mark and another of the rim profile showing wall thickness. The app can narrow the likely maker and line quickly, which points you toward the right collector reference for that specific producer. If the result suggests a rare early form or an unusual pattern, treat that as a prompt for deeper verification rather than a final answer.

Sources