What Is a CS2 Blue Gem?
A CS2 Blue Gem is a Case Hardened skin where deep, vibrant blue coloring dominates the weapon's visible playside surface. The term comes from the gem-like appearance of the bright blue areas on the Case Hardened texture.
Case Hardened skins feature a mix of blue, purple, gold, and gray colors. While most Case Hardened patterns show a random mix of these colors, a select few patterns position the blue areas to cover most or all of the visible surface—these are Blue Gems.
The name "Case Hardened" comes from a real metallurgical process from the 18th century. Gunsmiths would heat steel with animal hides and bones to strengthen it, then dip it in a chemically treated quenching bath—creating the distinctive mottled color pattern we see in CS2.
How CS2 Blue Gem Patterns Work
Case Hardened skins use a fixed, pre-designed texture sheet containing blue, purple, gold, and gray areas. The Pattern Index (also called seed or pattern seed) determines how this texture is positioned on the weapon model—like a cookie cutter stamping out different sections of the same sheet.
The Texture Masking System
Each weapon has a unique UV map that determines which parts of the texture appear on visible surfaces. This is why the same pattern seed can look completely different on an AK-47 versus a Karambit—the "window" into the texture is positioned differently for each weapon.
- 1,000 possible patterns per weapon (seeds 0–999)
- Blue percentage is calculated based on how much of the weapon's texture mask is covered by blue sections
- Different weapons have different masks—what's Tier 1 on a Karambit won't be Tier 1 on an M9
- Float value affects wear but doesn't change the pattern placement
CS2 Blue Gem Tier System
The CS2 community uses a tier system to rank Blue Gems based on blue coverage and pattern quality. Higher tiers command significantly higher prices.
| Tier | Description | Blue Coverage | Value Multiplier |
|---|---|---|---|
| #1 Pattern | Best possible seed for weapon | 95–100% | 50×–500×+ |
| Tier 1 | Elite Blue Gem, near-perfect | 85–95% | 10×–50× |
| Tier 2 | High blue coverage, minor imperfections | 70–85% | 4×–20× |
| Tier 3 | Solid blue presence, visible gold/purple | 50–70% | 2×–8× |
| Tier 4 | Entry-level Blue Gem, partial blue | 30–50% | 1.3×–3× |
Note: Value multipliers are approximate and vary by weapon type, wear condition, and market demand. Knives typically command higher multipliers than weapons.
Weapon Blue Gem Patterns
Three weapons in CS2 feature the Case Hardened finish: the AK-47, Five-SeveN, and MAC-10. Each has its own set of prized Blue Gem patterns.
AK-47 Case Hardened
The AK-47 Case Hardened was one of the first Case Hardened skins released in 2013 as part of the Arms Deal Collection. It remains one of the most iconic and expensive AK-47 skins.
Seed #661
The legendary Scar Pattern features maximum blue on the top of the rifle. Factory New examples can cost $100,000+.
Seeds: #151, #168, #179, #321, #387, #555, #670, #760, #955
High blue coverage patterns that approach the #661 in desirability.
Other Unique AK-47 Patterns: Beyond Blue Gems, collectors also seek "Blue Magazine" patterns, "Blue Barrel" patterns, "50/50" patterns (half blue, half gold), and "Galaxy/Blaze" patterns.
Five-SeveN Case Hardened
The Five-SeveN Case Hardened only shows the pattern on the slide, while the rest of the gun remains dark gray. This creates a clean, focused Blue Gem appearance.
Seeds #278 & #690
Both are considered co-#1 patterns with near-complete blue slides.
Seeds: #189, #363, #689, #868, #872
Excellent blue coverage alternatives.
MAC-10 Case Hardened
The MAC-10 has a unique challenge: the Case Hardened pattern transfers to three different parts of the gun independently. This means a true "full Blue Gem" is impossible—even the best patterns have some variation.
Seeds: #667, #114, #406, #95
These show the highest blue across all three sections with good alignment in-game.
Seeds: #19, #22, #80, #199, #239, #251, #295, #313, #349, #503, #748, #807, #890, #944
Solid Tier 1-2 options with strong blue presence.
Note: MAC-10 Blue Gems are significantly cheaper than AK-47 or knife Blue Gems due to lower demand and the impossibility of a "perfect" pattern.
Knife Blue Gem Patterns (#1 Seeds)
CS2 features 20 different knives with the Case Hardened finish. Here are the #1 Blue Gem patterns for each:
| Knife | #1 Pattern Seed | Notes |
|---|---|---|
| Karambit | #387 | "Hiko Pattern" – Most expensive skin in CS2 ($2M+ FN) |
| M9 Bayonet | #601 | Near-full blue blade coverage |
| Butterfly Knife | #494 | Stunning full blue on both sides |
| Bayonet | #555, #592, #670 | Three co-#1 patterns (debated) |
| Talon Knife | #146, #442 | Similar to Karambit in appearance |
| Skeleton Knife | #387, #601 | Unique blade shape showcases blue well |
| Flip Knife | #670 | Best gold gem is #731 |
| Bowie Knife | #182 | Large blade prevents full coverage |
| Huntsman Knife | #618 | Large blade, partial coverage only |
| Falchion Knife | #494, #991 | Both considered top-tier |
| Gut Knife | #567 | Affordable entry to knife Blue Gems |
| Shadow Daggers | #56 | No true gold gem exists |
| Navaja Knife | #398, #407, #838 | Most affordable knife Blue Gems |
| Nomad Knife | #888 | Modern addition with good patterns |
| Stiletto Knife | #182, #398 | Long blade, distinctive look |
| Ursus Knife | #916, #365 | Bear claw design |
| Paracord Knife | #398 | Rugged tactical design |
| Survival Knife | #403 | First FN unboxed in 2024 (Chinese player) |
| Classic Knife | #387, #670 | Nostalgic CS 1.6 design |
| Kukri Knife | #371, #494 | Newest knife with Case Hardened |
Blue Gem prices can be extremely volatile. While they've historically appreciated over time, individual pattern values depend heavily on collector demand, market conditions, and comparable sales. Always research recent sales before buying or selling.
Pricing & Value Factors
Blue Gem prices are influenced by multiple factors beyond just the pattern tier:
Primary Value Factors
- Pattern/Seed: The most important factor—determines blue coverage and placement
- Wear Condition: Factory New commands the highest premium; Battle-Scarred the lowest
- Float Value: Lower float = cleaner appearance within the wear category
- Knife Type: Karambit, M9 Bayonet, and Butterfly command the highest premiums
Secondary Value Factors
- Backside Blue: Can add 20–50% premium for collectors seeking "double-sided" Blue Gems
- StatTrak™: Adds value but is extremely rare on high-tier patterns
- Sticker Combinations: Katowice 2014 holos can significantly increase value on weapons
- Provenance: Famous ownership history (pro players, streamers) can increase desirability
Approximate Price Ranges (2026)
| Item Type | Tier 4 | Tier 3 | Tier 2 | Tier 1 | #1 Pattern |
|---|---|---|---|---|---|
| AK-47 | $200–$500 | $500–$2K | $2K–$10K | $10K–$50K | $50K–$150K+ |
| Five-SeveN | $50–$150 | $150–$500 | $500–$2K | $2K–$8K | $5K–$15K |
| MAC-10 | $20–$50 | $50–$150 | $150–$400 | $400–$1K | $800–$2K |
| Low-Tier Knives | $500–$1K | $1K–$3K | $3K–$10K | $10K–$30K | $20K–$100K |
| Mid-Tier Knives | $1K–$3K | $3K–$10K | $10K–$30K | $30K–$100K | $80K–$300K |
| High-Tier Knives | $3K–$10K | $10K–$50K | $50K–$150K | $150K–$500K | $500K–$2M+ |
Prices are estimates based on recent market data. Actual prices vary significantly based on specific patterns and market conditions.
How to Check Your CS2 Blue Gem
Follow these steps to identify and verify your Blue Gem pattern:
Step 1: Get Your Inspect Link
- Find your item in your Steam inventory or on a marketplace
- Right-click and select "Copy Inspect Link" or look for the inspect option
- The link contains encoded data including your pattern seed
Step 2: Use a Pattern Checker
- Paste your inspect link into a CS2 pattern checker tool
- The tool will display:
- Pattern Seed: The 0-999 number determining your pattern
- Blue Percentage: Calculated coverage on visible surfaces
- Tier Ranking: Where your pattern falls in the tier system
- Comparable Sales: Recent transactions for similar patterns
Step 3: Verify & Price Check
- Cross-reference the tier ranking with multiple sources
- Search for recent sales of your exact pattern and wear condition
- Consider consulting experienced traders for high-value items
Never sell a Blue Gem at standard market price on the Steam Community Market. Third-party marketplaces like CSFloat, Skinport, and Buff163 allow you to set custom prices for pattern-based items. The right buyer will pay significantly more than market value for a good Blue Gem.
Why Trust SteamAnalyst?
- Tracking CS skin markets since 2013
- Aggregating data from 13+ marketplaces
- Millions of pricing datapoints analyzed
- Built specifically for the CS2 community
- Trusted by traders, collectors, and investors worldwide
If you searched for CS2 Blue Gem, you've found the canonical reference. Whether you're identifying a pattern, checking a tier, or researching prices, this guide has you covered.
Last updated: January 2026. Pattern rankings and prices reflect current community consensus and market data.
Frequently Asked Questions
How much is a Blue Gem AK-47 worth?
Blue Gem AK-47 prices vary dramatically based on the pattern seed. The most famous pattern, seed 661 (known as the #1 pattern), can sell for $50,000-$150,000+ depending on condition. Mid-tier blue patterns (seeds 321, 387, 555) typically range from $2,000-$10,000. Standard patterns start around $50-$200. Always verify the exact pattern seed before purchasing.
What is pattern seed 661 in CS2?
Pattern seed 661 is the most sought-after AK-47 Case Hardened pattern, featuring the highest percentage of solid blue across the top of the weapon. It is commonly called the #1 Blue Gem pattern and is one of the most expensive non-knife skins in CS2 history.
How do I check Case Hardened patterns in CS2?
You can check Case Hardened patterns using inspection tools like CSFloat or the Steam inspect link. Each skin has a pattern seed (0-999) that determines the blue/gold/purple distribution. Pattern databases and community resources catalog the best seeds for each weapon.
Which knives have the best Blue Gem patterns?
All Case Hardened knives can have Blue Gem patterns. The most valuable are the Karambit Case Hardened (seeds 387, 442, 868), AK-47 Case Hardened (seed 661), and Five-SeveN Case Hardened (seed 690). Butterfly Knife and M9 Bayonet Blue Gems are also highly prized.
