Neptunite

Add one script tag to your page:

<div data-gemfyi="entity" data-slug="neptunite"></div>
<script src="https://cdn.jsdelivr.net/npm/gemfyi-embed@1/dist/embed.min.js" defer></script>

Embed as an iframe:

<iframe src="https://gemfyi.com/iframe/entity/neptunite/?style=modern&theme=light" width="420" height="400" frameborder="0" loading="lazy" style="border:0;border-radius:10px;max-width:100%"></iframe>

Paste the URL in WordPress, Medium, or Ghost:

https://gemfyi.com/ar/gems/neptunite/

Shields.io-compatible SVG badge:

Neptunite badge ![Neptunite](https://gemfyi.com/badge/entity/neptunite.svg)

Web Component:

<gemfyi-entity slug="neptunite"></gemfyi-entity>
<script src="https://cdn.jsdelivr.net/npm/gemfyi-embed@1/dist/embed.min.js" defer></script>

Physical & Optical Properties

Mohs Hardness 5,0 – 6,0
Specific Gravity 3,19 – 3,23
Refractive Index 1,692 – 1,734
Crystal System Monoclinic
Luster Vitreous
Cleavage Perfect
Fracture Conchoidal
Color various
Birefringence 0,029
Pleochroism Pale yellow - yellow-orange - orange to red-brown

Mohs Hardness

Mohs Hardness: 5,0 – 6,0
1 Soft10 Hard

Crystal System

β a b c Monoclinic a ≠ b ≠ c, α = γ = 90°, β ≠ 90°

Value & Market

Price Tier Budget (< $50/ct)

About Neptunite

Neptunite is a sodium potassium lithium iron manganese titanium silicate mineral forming striking jet-black to very dark red prismatic crystals with a vitreous to resinous luster, named for its association with aegirine (also named for a sea deity). It occurs in nepheline syenite intrusions and natrolite veins and is famously found in Benitoite gem mine in San Benito County, California, USA, often as well-formed black crystals alongside the blue benitoite. Rare transparent deep red to reddish-brown faceted neptunite is a notable collector gem.

Jewelry Use

Durability 4/10

Science FYI Family

Frequently Asked Questions

What is Neptunite?
Neptunite is a sodium potassium lithium iron manganese titanium silicate mineral forming striking jet-black to very dark red prismatic crystals with a vitreous to resinous luster, named for its association with aegirine (also named for a sea deity). It occurs in nepheline syenite intrusions and natr
What is the hardness of Neptunite?
Neptunite has a Mohs hardness of 5.0 to 6.0, making it moderate for use in jewelry.
What color is Neptunite?
Neptunite is primarily Various.
How much does Neptunite cost?
Neptunite falls into the Budget (< $50/ct) price range. Prices vary based on color, clarity, cut, and origin.
What is the crystal system of Neptunite?
Neptunite belongs to the Monoclinic crystal system.

More Semi-Precious Gems Gems