Lake County Diamonds are naturally occurring, highly transparent, doubly terminated quartz crystals found in volcanic soils. They are prized by collectors for their naturally faceted, brilliant appearance that often requires no cutting or polishing to exhibit a gem-like quality.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralcommonQuartz family

Lake County Diamond

Also: Clear Lake Diamond

Hardness: 7
Luster: Vitreous
Streak: White
Transparency: Transparent

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Is this lake county diamond?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch lake county diamond with a known reference. Lake County Diamond sits at Mohs 7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Lake County Diamond leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Lake County Diamond typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless.
5
Look at form & habit
Crystal system: trigonal. Typical habit: doubly terminated crystals.

Often confused with

Lake County Diamond vs. its common look-alikes — and how to tell them apart in the field.

Often found alongside lake county diamond

Minerals reported to co-occur with lake county diamond. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: SiO₂
Mohs hardness: 7
Density: 2.65 g/cm³
Colors: Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Trigonal
Crystal habit: Doubly Terminated Crystals
Cleavage: None
Rarity: Common
Uses: Collector, Lapidary
Host rock: Volcanic Deposits
Typical price: $5-50 for thumbnail and small crystals

Where rockhounds find lake county diamond

Classic worldwide localities

Lake County, California, USA
Clear Lake, California, USA

Field-hunting tip

Look in volcanic deposits country — that is the host setting where lake county diamond typically forms. If you start seeing obsidian, basalt in float, you are in the right ground. Field specimens usually show a doubly terminated crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify lake county diamond?+

Mohs hardness is 7. It typically shows a vitreous luster. The streak is white. Common colors include colorless.

Where is lake county diamond found?+

Notable localities include Lake County, California, USA; Clear Lake, California, USA.

How much is lake county diamond worth?+

Typical asking prices fall in the range of $5-50 for thumbnail and small crystals. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like lake county diamond?+

Lake County Diamond is most often confused with Herkimer Diamond, Quartz. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with lake county diamond?+

Lake County Diamond commonly co-occurs with Obsidian, Basalt. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does lake county diamond form in?+

Lake County Diamond typically forms in volcanic deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is lake county diamond used for?+

Lake County Diamond is used in collector, lapidary.

Find lake county diamond on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.