Comparison · Materials
Blue Goldstone vs Slag Glass
Blue Goldstone and Slag Glass are easy to confuse because both are materials. Both sit near Mohs 5.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Blue Goldstone and Slag Glass
- Both sit near Mohs 5.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Hold a thin edge to the light: Blue Goldstone is opaque, Slag Glass is translucent.
- They overlap in blue, but Slag Glass also comes in green, black, brown, and white.
Blue Goldstone vs Slag Glass properties
| Property | Blue Goldstone | Slag Glass |
|---|---|---|
| Type | Materials | Materials |
| Mohs hardness | 5.5 | 5.5 |
| Luster | vitreous | vitreous |
| Streak | White to colorless | White to colorless |
| Transparency | opaque | translucent |
| Specific gravity | 2.5 | 2.5 |
| Crystal system | amorphous | amorphous |
| Common colors | Dark Blue, Navy, Sparkly, Metallic specks | Blue, Green, Black, Brown, White, Swirled |
| Rarity | common | common |
| Typical specimen value | $3–$80+ | $1–$80+ |
Which is more valuable?
Blue Goldstone is usually the more valuable of the two: a typical collector specimen runs about $15 against $10 for Slag Glass, and premium Blue Goldstone can reach $80 or more.
About Blue Goldstone
Blue Goldstone is a manufactured dark blue aventurine glass with tiny sparkling metallic inclusions.
About Slag Glass
Slag Glass is glassy industrial byproduct or manufactured glass with swirled colors, sometimes collected or knapped like stone.
Blue Goldstone vs Slag Glass FAQ
Is Blue Goldstone the same as Slag Glass?
No. Both are materials, but they are distinct species with different hardness, streak or luster. Both sit near Mohs 5.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Blue Goldstone from Slag Glass?
Both sit near Mohs 5.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Hold a thin edge to the light: Blue Goldstone is opaque, Slag Glass is translucent. They overlap in blue, but Slag Glass also comes in green, black, brown, and white.
Which is harder, Blue Goldstone or Slag Glass?
They are about equally hard, both near Mohs 5.5.
Which is more valuable, Blue Goldstone or Slag Glass?
Blue Goldstone is usually the more valuable of the two: a typical collector specimen runs about $15 against $10 for Slag Glass, and premium Blue Goldstone can reach $80 or more.
