Fall 2026

Gems: the Science Behind the Sparkle

GEOSCI 331 explores the formation, collection, properties, and treatment of popular gemstones.

offering recorded1–2 credits
Recorded instructors · Fall 2026 Huifang Xu3.5/5

Summary

1 / 6

Students must manage numerous PDF lectures and create study aids like diagrams and spreadsheets. Exams are timed, 30-question tests that require linking multiple details from the lectures.

Grade history

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average GPA
letter grades
A
AB
B
BC
C
D
F

All recorded terms · compare terms & instructors

Prerequisites

Course map

Junior standing

  • Junior standing
GEOSCI 331

This is a best-effort interpretation; check the catalog requirements above.

Prerequisite text tree
  • Junior standing

Professors

Fall 2026
/5Adjusted rating
/5RMP difficulty
captured reviews
About this rating

Raw average: 3.33/5 from 21 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.

For this course: 3.5/5 raw quality · 2.7/5 difficulty · 6 reviews

RMP profile ↗ · All captured review dates; profile matched by name.

Huifang Xu is described as a nice professor who teaches an easy class with easy tests, leading to high grades. Reviewers found the material interesting and the workload manageable, with one noting that earning less than an A is difficult.

Some reviewers report significant challenges, citing extremely nitpicky exam questions that require linking trivial details. Concerns include timed exams requiring all lectures, incorrect grading due to technology issues, and slow email responses from the instructor.

Recent recorded grades — Spring 2025: 3.45 GPA, 73.6% A/AB (n=276 letter grades); Fall 2025: 3.76 GPA, 89.7% A/AB (n=234 letter grades); Spring 2026: 3.84 GPA, 92.5% A/AB (n=280 letter grades).

Historical instructors & teaching patterns

HUIFANG XU is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.

Recorded history may be incomplete and does not establish a future schedule.

Calendar & sections

Fall 2026

Schedule loads here as you scroll.

SectionModeEnrolled / capacityWaitlist
LEC 001Online Only250 / 2500

Times are Central. Select a meeting for details; export includes recorded dates for the selected sections. Enrollment reflects scan time.

Meeting source records

No records available.

Student experience

the class

Reviewers describe the course as easy with straightforward tests. Some find the material interesting and the professor nice, noting that earning a high grade is straightforward.

Recent recorded grades — Spring 2025: 3.45 GPA, 73.6% A/AB (n=276 letter grades); Fall 2025: 3.76 GPA, 89.7% A/AB (n=234 letter grades); Spring 2026: 3.84 GPA, 92.5% A/AB (n=280 letter grades).

difficulty & workload

Students must manage numerous PDF lectures and create study aids like diagrams and spreadsheets. Exams are timed, 30-question tests that require linking multiple details from the lectures.

One reviewer reports frustration with nitpicky exam questions and incorrect grading, noting that the instructor is slow to respond to emails regarding grade disputes.

Topics

  • Gemstone formation
  • Gemstone collection
  • Gemstone properties
  • Gemstone treatment

Grades

Historical instructor

Fall 2026 · Projected

Before grades are released

– average GPA

Approximate 80% prediction interval

About this estimate

The course’s semester-average GPA, not an individual student’s grade. The center uses 5 same-season terms, weighted toward recent results.

The range uses the finite-sample 80th-percentile rank of absolute errors from earlier same-season forecasts. Each forecast uses only records from earlier terms. At least four forecasts are required; bounds are rounded outward and limited to 0–4. This is an empirical estimate: changing instructors or grading policies can reduce its coverage.

8 earlier forecasts · 0.23 GPA average error.

Grades over time

Through Fall 2026

More grade details Grade mix, volume & source data

Where this course fits relative to

Latest available grades · Spring 2026 · all course levels

GPA

Higher than % of other courses in this group.

Course GPAs · red marks this course’s range

letter grades

More recorded grades than % of other courses in this group.

Typical course in this group: letter grades.

About this comparison

1283 courses over the same term, each with at least 30 recorded letter grades. Cross-listed courses count once. GPA is not a measure of difficulty or teaching quality. The typical course is the median by recorded grade count; tied values are not counted as lower. Grade counts describe course scale, not unique students or typical section size.

Descriptions compare GPA with this group’s average: at least 0.20 higher or lower; otherwise close to average. Section size uses median recorded enrollment: small up to 30, mid-sized 31–99, large 100+. Lectures and discussion/lab sections are described separately.

Sources & history

UW–Madison

Catalog & offerings

Descriptions, prerequisites, and recorded course offerings.

Catalog observation history

Observations at scan time; dates do not imply when a catalog change took effect.

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Selected offering source records
GEOSCI 331 · Fall 2026

Gems: The Science Behind the Sparkle

Recorded 2026-09-07
Raw records
[
  {
    "run_id": "20260907T155543-ce3781c4",
    "semester": "1272",
    "observed_at": "2026-09-07 15:55:43.033547+00:00",
    "offering_id": "1272:420:022130",
    "course_id": "GEOSCI 331",
    "course_uid": "course_81f4461a09a3e6c844c539a7",
    "term_id": "1272",
    "source_course_id": "022130",
    "source_subject_id": "420",
    "title": "Gems: The Science Behind the Sparkle",
    "credits_min": 1,
    "credits_max": 2,
    "typically_offered": "Fall, Spring"
  }
]
Rate My Professors

Student reviews

Original comments behind the course and instructor summaries.

Read original reviews
Download part 1
Madgrades

Grade history

Recorded grade distributions by term, section, and instructor.

Explore recorded grades
Dataset & model

Recorded 2026-09-07

Download the original dataset
Model outputs & technical records
nvidia/Qwen3.6-35B-A3B-NVFP4
LLM outputs across runs
Download part 1
Full model traces

Recorded model configuration, reasoning, and tool conversations.

Download part 1
Model & dataset provenance
{
  "model": "nvidia/Qwen3.6-35B-A3B-NVFP4",
  "model_revision": "1355db6a052410cfd62085d94b58866fd0f2c3c5",
  "task_version": "14",
  "output_id": "2f3d1ff4b9bc6d8c48daf1c549952885e3cfb42ef2d690e1b27fa671fb76d9aa",
  "requirements_status": "valid",
  "dataset_revision": "e243353dcb7d79b7247ced91d69443ef4c2a6349",
  "observed_at": "2026-09-07 15:55:43.033547+00:00"
}