Hogarthite is an extremely rare magnesium titanium-aluminum oxide mineral discovered within the alkaline pegmatites of the Khibiny Massif. It typically occurs as small tabular crystals associated with nepheline syenites and is primarily of interest to advanced systematic mineral collectors due to its rarity and complex chemical structure.

Hardness

3-4

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrarenull family

Hogarthite

Hardness: 3-4
Luster: Vitreous
Streak: White
Transparency: Transparent

No image

Is this hogarthite?

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 hogarthite with a known reference. Hogarthite sits at Mohs 3-4 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Hogarthite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Hogarthite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, pale yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals.

Often confused with

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

mineral

Sapphirine

Mohs 7.5

How to tell apart: Sapphirine is the harder of the two (Mohs 7.5 vs. 3-4).

Compare →

Often found alongside hogarthite

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

All properties

Chemical formula: Mg(Al₆Ti₃)O₂₀
Mohs hardness: 3-4
Density: 2.98 g/cm³
Colors: Yellow Pale Yellow
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Alkaline Igneous Rocks
Typical price: expensive

Where rockhounds find hogarthite

Classic worldwide localities

Khibiny Massif, Russia

Field-hunting tip

Look in alkaline igneous rocks country — that is the host setting where hogarthite typically forms. If you start seeing nepheline, aegirine, microcline in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hogarthite?+

Mohs hardness is 3-4. It typically shows a vitreous luster. The streak is white. Common colors include yellow, pale yellow.

Where is hogarthite found?+

Notable localities include Khibiny Massif, Russia.

How much is hogarthite worth?+

Typical asking prices fall in the range of expensive. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like hogarthite?+

Hogarthite is most often confused with Sapphirine. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with hogarthite?+

Hogarthite commonly co-occurs with Nepheline, Aegirine, Microcline, Titanite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does hogarthite form in?+

Hogarthite typically forms in alkaline igneous rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is hogarthite used for?+

Hogarthite is used in collector.

Find hogarthite on the map

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