Most pieces are decorative in nature, sprucing up side tables and bookshelves. Mychelle is a writer and web designer who is passionate about a wide variety of topics and enjoys sharing her knowledge with readers. These three manufacturers are very well known in the United Kingdom. This does use the broader definition of slag glass that includes white marbling produced through any method. Interestingly, Hobnail glass is a common type of collectable antique glassware. After all, part of the fun of collecting antique glass is solving the hidden mysteries embedd, What Is Vaseline Glass? Some well-known slag glass manufacturers include Sowerby, Davidson, and Greeners. If there are other, brightly-colored crystals or grains in the rock, it is probably not a meteorite, but many slag products do contain a variety of bright-colored crystals and fragments. Portland slag cement, which is most commonly used in the region, was used for the study complying with IS 455 [21].Its specific gravity was 2.87 having initial and final setting times of 70 minutes and 480 minutes, respectively.For fine aggregate, natural sand was used, having a maximum size of 4.75 mm.Its specific gravity was 2.72, conforming to Zone-III, and having a fineness modulus of 2.313. So keep your eye out for glass made by these companies from the 19th century. This is listed on the bottom of most slag glass items, especially lamps. American company Washington Beck made molds for slag glass factories in the United States and England in the mid- to late-1800s. [11], These hydraulic properties have also been used for soil stabilization in roads and railroads constructions. or Best Offer. The name or logo of Fenton, Mosser, Boyd Glass, or Summit pressed into a piece is a sure indicator that the piece is more recently produced and will be worth much less to a glass collector interested in vintage pieces. Save my name, email, and website in this browser for the next time I comment. Without advertising income, we can't keep making this site awesome for you. Instead of slag, they mixed purple glass with a white-colored glass that did not contain any iron slag. Nearby Recently Sold Homes. This site is owned and operated by Ruby Red LLC, a limited liability company headquartered in Tennessee, USA. Slag glass is a type of pressed glass that is known for its brilliant and vibrant colors. $24.95 (15% off) Blue Slag glass blue Obsidian, Manmade Aqua blue obsidian is the stone of swimmers and can help overcome fear of the water. Although, the majority of slag glassware was created as decorative pieces. All rights reserved. Metal furnace slag can range from glassy to dull and stony in appearance and, when scratched, can range from hard to chalky. Slag glass is no longer produced as it once was. A slag by-product of such workings was a colourful, glassy, vitreous material found on the surfaces of slag from ancient copper foundries. United States. During smelting, when the ore is exposed to high temperatures, these impurities are separated from the molten metal and can be removed. Slag glass producers mark their products with the companys initials or the companys logo. [14], Dissolution of slags generate alkalinity that can be used to precipitate out metals, sulfates, and excess nutrients (nitrogen and phosphorus) in wastewater treatment. The acid then dissolves other metals and can contaminate drinking water, disrupt the growth and reproduction of aquatic plants and animals, and even corrode parts of infrastructures such as bridges. How to Cut Hand Rolled Art Glass | Delphi Glass - YouTube. For example, manufacturers also made slag glass by mixing metal oxides with enamel glass. Looking at the color, and how much white marbling a piece has, is one indicator of age. Some show flow features in the glass and others have flat surfaces from having solidified in a contained space. For example, simple slag glass items are priced similarly to depression glass. [4]. Despite its rarity, you can still find slag glass items in modern homes. It's formed by heating ores (rock) to high temperatures. Other types of metal ores produce different colors of slag when they are refined. [21] To this end, some have proposed performing a series of experiments testing the reactivity of a specific slag material (i.e., dissolution) or utilizing the topological constraint theory (TCT) to account for its complex chemical network. What Is Slag Glass? [5], In nature, iron, copper, lead, nickel, and other metals are found in impure states called ores, often oxidized and mixed in with silicates of other metals. Slag glass antique items can run anywhere in value from a low of $50 to a high of $1,500. Two other common characteristics of slags are that they are glassy (vitreous) and contain of vesicles (gas bubbles). 6 Vintage Sneakers That Are Still in High Demand. These compounds could be harmful not only for environment but also for human health [9,10]. Slag is usually a mixture of metal oxides and silicon dioxide; however, slags can contain metal sulfides and elemental metals. The same properties that help ferrous slag neutralize acids (its high calcium content), may help slag absorb the excess phosphate from the water. For todays collectors, slag glass is a greatly sought-after item that can go for a lot of money. Secure .gov websites use HTTPS This will ensure that the money you are spending is worth it. During this time, it was also used as an aggregate and have begun being integrated into the cement industry as a geopolymer. or Best Offer. However, the most important application is construction. Unlike any other type of glass, slag glass is not transparent. Slag from steel mills in ferrous smelting is designed to minimize iron loss, which gives out the significant amount of iron, following by oxides of calcium, silicon, magnesium, and aluminium. Traditional slag glass gets its creamy colored streaks from something called slag. Grapevine, TX 76051. Ruby Red LLC is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. Manufacturers usually make slag glass by mixing this silicate slag with clear glass. In many smelting processes, oxides are introduced to control the slag chemistry, assisting in the removal of impurities and protecting the furnace refractory lining from excessive wear. Introduction: My name is Dr. Pierre Goyette, I am a enchanting, powerful, jolly, rich, graceful, colorful, zany person who loves writing and wants to share my knowledge and understanding with you. Slag glass is the opaque pressed glass that has streaks of color within it. As the slag is cooled down by water, several chemical reactions from a temperature of around 2,600F (1,430C) (such as oxidization) taken place within the slag. This is because the top manufacturers of the day often did leave any identifying brand marks on the fixtures. Most homes in the late 19th century and even some older homes today could be found using a slag glass lampshade as decor. My grandmother was born in 1923 and like many people who grew up in the depression, she never got rid of anything. Real slag glassware will also never just be one solid color, it will always be blended. Is it slag? As with many other types of vintage glassware, the slag glass technique can be found in all sorts of different pieces, decorative or functional. $86.99. 701 South Main Street, #103. Not only that, but it can even reduce acids that have built up in soils. Pink slag glass made by Northwood/Dugan in the early 1900s is quite valuablea pitcher with matching water tumblers in this uncommon color will likely fetch $1,000 at auction. How do you identify glass slag rocks? Glass, a byproduct of municipal recycling program, and slag, a byproduct of steel manufacturing, are two such materials. The company, based in Jeannette, Pennsylvania, rebranded in 1898 and took on the name Jeannette Glassware. Slag usually refers to a glassy by-product of smelting ores to retrieve the metal. The value of slag glass items can also be determined by the condition of the item. The marbling is sometimes compared to tortoiseshell. Slag glass has something that cannot be found in imperial glass, uranium glass, milk glass, depression glass, carnival glass, or any other type of vintage collectors glassware. Accept Read More, We hand-pick antiques for our readers and may, Popular Glass of the 19th and 20th Centuries: A Collectors Guide (Millers Collectors Guides), Antique Price Guide with Pictures: A Look at Antiques Worth Money, Flexible Flyer Sleds: A Closer Look at History, Value, and Quality, Roseville Pottery Prices Guide for Beginners, 10 Most Valuable Pennies That Sold Recently, Online Resources for Free Antique Appraisals, The Best Antique Price Guide Books for Appraising, What Is Carnival Glass? How do you grind glass without a grinder? 10.2.2 Blast furnace slag. Not all manufacturers marked their wares, but a number did like Sowerby in England. . Slag is also used as aggregate in asphalt concrete for paving roads. See if holding onto your favorite action figures as a kid has paid off. Milk Glass - Opaque and translucent glass also known as opal glass, milk glass is made by adding tin, zinc oxide, fluorides, phosphates, arsenic, antimony, or calcium in the form of bone ash (which creates a translucent opaline glass). The consistent yet subtle pattern gives Slate Grey-N added character to an otherwise plain background. Thanks Virginia. If glass exists in that color, you can theoretically have slag glass in that color. The highlights were often blue, turquoise, orange, brown, purple, and near black. [5], Non-ferrous slag is produced from non-ferrous metals of natural ores. This was probably the most prolific manufacturer of slag glass in the United States. Metal furnace slag can range from glassy to dull and stony in appearance and, when scratched, can range from hard to chalky. [5], Slags can serve other purposes, such as assisting in the temperature control of the smelting, and minimizing any re-oxidation of the final liquid metal product before the molten metal is removed from the furnace and used to make solid metal. Many manufacturers used colored slag glass to create elaborate patterns in the lamp bases and shades, while others used the glass to create everyday scenes and landscapes. Reviews: 85% of readers found this page helpful, Address: Apt. She has also managed an online antiques community. Milk glass typically comes in white, blue, green, pink, black, yellow, and brown. True slag glass is marbled and has a variety of bright colors. What was Juliet's last words before she died? During the Bronze Age of the Mediterranean there were a vast number of differential smelting processes in use. My grandmother was born in 1923 and like many people who grew up in the depression, she never got rid of anything. Check the bottom or inside of an item for either a name or logo of a manufacturer. The History, Popularity, Value & How To Identify! Serious antique glass collectors will be familiar with "slag glass" which became popular in the late 1800s and is still made today. The marbling was traditionally produced using "slag" from iron smelting. It was also ground into powder to add to glazes for use in ceramics. Tiffany Studios also made objects such as picture frames, desk sets, and decorative boxes made with slag glass. A .gov website belongs to an official government organization in the United States. Furthermore, slag can be classified based on the abundance of iron among other major components. [22], Slags are transported along with slag tailings to "slag dumps," where they are exposed to weathering, with the possibility of leaching of toxic elements and hyperalkaline runoffs into the soil and water, endangering the local ecological communities. Ruby Red LLC is compensated for referring traffic and business to these companies. A similar look can be produced using multiple colors of glass mixed together, each individually colored using various compounds. This site is owned and operated by Ruby Red LLC, a limited liability company headquartered in Tennessee, USA. In this case, the slag used for marbling glass is produced when iron is heated during the production process. Modern day slag glass manufacturers in the U.S. include Fenton, Mosser, Summit and Boyd Glass. Slag is composed primarily of silica and lime, with concentrations of other minor constituents, including alumina, magnesia, and other compounds. This color pattern led to the "brown malachite" and "brown marble" names. It was very popular as it is commonly used to create lampshades. Although the construction industry does use some slag as an aggregate, most is simply discarded. [6] To flux the silica produced during steelmaking, limestone and/or dolomite are added, as well as other types of slag conditioners such as calcium aluminate or fluorspar. SOLD FEB 10, 2023. Learning how to identify and value this glass can help if you are looking to collect or just learn more about this interesting glassware. What is the safest antacid to take long-term? Finally, iron meteorites are strongly magnetic and slag is not. According to Norman Webber, some companies referred to slagware as end of the day wear because glassmakers collected slag from the surface of iron right before they poured it at the end of the day. I grew up going to antique stores and markets with my mom and grandmother. The smelting of copper, lead and bauxite in non-ferrous smelting, for instance, is designed to remove the iron and silica that often occurs with those ores, and separates them as iron-silicate-based slags. Many antique lamps of these periods were made with stained glass, rather than slag glass, and a careful review of the glass opacity and patterns is necessary to determine the difference. It is hard to keep fragile glass intact for decades. Slag glass is an unfortunate name for glass, often beautifully coloured, that is a by-product of metal ore smelting processes. You can determine antique slag glass with a few steps: Slag glass antique items can run anywhere in value from a low of $50 to a high of $1,500. Slag is the collection of compounds that are removed. Slag glass is a man-made opaque base glass with marbelized swirls in a different color. Slag is used to refer to the by-product that shows up when various ores and metals are smelted. Some of the most popular manufacturers were Miller, Bradley & Hubbard, Empire Lamp Manufacturing Company, Pittsburgh Lamp, Brass and Glass Company, H.E. 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