Identification guide · Igneous Rocks
How to Identify Aplite
Aplite is usually white, pink, and cream with a dull luster and is opaque. It has a Mohs hardness of 6. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. Its streak is white to pale pink. It is most often confused with Monzonite, Granite, and Tonalite; the tests below separate them.
Aplite identification checklist
| Color | White, Pink, Cream, Light gray, Tan | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Dull | Compare a fresh surface with glass and metal; this luster is softer than either. |
| Transparency | Opaque | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 6 | It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. |
| Streak | White to pale pink | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | Variable by quartz and feldspar grains | |
| Fracture | Granular to uneven | |
| Specific gravity | 2.65 | Ordinary rock-like heft (specific gravity about 2.65), similar to quartz. |
Aplite look-alikes and how to tell them apart
Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Aplite vs Monzonite →
Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Aplite vs Granite →
Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Aplite vs Tonalite →
Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Field tips
- Look for a light-colored, sugary, fine-grained granitic texture.
- Aplite is usually finer and more uniform than pegmatite.
- It commonly appears as veins or dikes associated with granite.
- Visible quartz and feldspar support the identification.
Aplite identification FAQ
How can you tell if a rock is Aplite?
Check the color (white, pink, cream, and light gray), the dull luster, a Mohs hardness of 6 and a white to pale pink streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Aplite?
Aplite has a Mohs hardness of 6. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will.
What is the difference between Aplite and Monzonite?
Aplite (Mohs 6, dull luster) and Monzonite (Mohs 6, dull luster) look alike, but hardness, streak and heft usually separate them. See the full Aplite vs Monzonite comparison for a side-by-side table.
Is Aplite worth anything?
Entry-level Aplite specimens sell for around $1, typical collector pieces about $10, and premium examples $75 or more depending on size, quality and locality.
What color is Aplite?
Aplite is most often white, pink, cream, and light gray. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
