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Based on all of the visual evidence combined, this bowl is an original Imperial Glass Company piece made during the Classic Era of Carnival Glass, specifically between 1909 and the late 1920s.

Final Consolidated Identification

Brand / Manufacturer: Imperial Glass Company (Bellaire, Ohio).
Pattern Name: "Diamond Ring" (characterized by the alternating diamond grids and teardrop panels).
Base Design: "Whirling Star" / "Hobstar" style collar base.
Production Period: 1909 – Late 1920s
- Imperial introduced its first iridescent carnival glass line (called "Rubigold" and "Peacock") in 1909 to compete directly with Fenton and Northwood. This specific design was manufactured during that initial, highly collectible peak era.
Color & Finish: Amethyst base glass with a plain, highly iridescent interior glaze.

An original 1910s bowl like this will not have any manufacturer marks or logos.

Finding no logo or signature on the bottom is completely expected for several historical reasons:

No Maker Marks on Classic Imperial Carnival: The vast majority of Imperial Glass Company’s carnival lines from the 1900s–1920s were never trademarked or physically stamped in the mold. Only Northwood regularly stamped their classic pieces (with their famous underlined "N").
Paper Labels: Instead of engraving or stamping the glass, manufacturers during this era typically placed temporary paper or foil stickers on the items when they shipped from the factory. Over the last century, these labels washed off or deteriorated.
The "IG" Confusion: If you ever see an Imperial Glass piece with an "IG" logo stamped into the glass (a capital G superimposed over an I), that is actually a sign of a modern reissue. Imperial introduced that physical trademark stamp in 1951 and used variations of it until they went bankrupt in 1984.

Because your bowl has a completely blank collar base with just the pressed star design, it aligns perfectly with being an authentic, early 20th-century antique rather than a mid-century reproduction.

Factors Impacting the Price

1. The Color Treatment

In carnival glass, color is judged by the base glass itself, not just the surface sheen. Imperial produced "Diamond Ring" heavily in Marigold (a bright orange/amber), which is very common and usually sells on the lower end ($20 – $35). Your amethyst/smoke base is more desirable to collectors, keeping it firmly in the mid-to-higher price bracket.

2. Condition of the Iridization

Because the interior of this bowl is completely smooth, any scratches from past use (like using metal spoons or stacking other bowls inside it) will stand out clearly against the mirror finish. A pristine interior surface commands a higher premium.

3. Sales Venue

If you sell it directly to an antique shop or a dealer, expect an offer of roughly 30% to 50% of the market value, as they need room for retail markup. Selling it yourself on an online marketplace will yield the closest amount to the full market price.

Attention all buyers!

Before you buy a product, please read the description of this product, check the photos, ask for more photos for details and ask additional questions for more details.

If you made an offer to purchase goods at a discount, this sale will be final and non-refundable. If you bought a product for the full price, you can return the product within the first week after the delivery of the product to your home if you find any defects or malfunction. Otherwise, the product is non refundable.

I apologize in advance if I made an inaccuracy in the description of the item being sold. That’s why I ask potential buyers for a discussion about the condition and quality of the product.

Sincerely,

Warehouse of Treasure